The strength of the North Korean Army particulalry its armoured strength is at issue, however my sources suggest a much higher initial strength than suggested in Joes Quote.
CHAPTER II, South to the Naktong, North to the Yalu
"By June 1950, the 105th Armored Regiment had become the 105th Armored Brigade with a strength of 6,000 men and 120 T34 tanks. Its equipment-tanks, weapons, and vehicles-was Russian-made. The brigade had three tank regiments-the 107th, 109th, and 203d-each with 40 tanks, and a mechanized infantry regiment, the 206th, with a strength of about 2,500 men. A tank regiment had three medium tank battalions, each having 13 tanks. The battalions each had three tank companies with 4 tanks to a company. Tank crews consisted of five men. Battalion, regimental, and division tank commanders each had a personal tank. The 105th Armored Brigade was raised to division status in Seoul at the end of June 1950 before it crossed the Han River to continue the attack southward".
[Parsifal Note: the North Korean Army also had approximately 7 battalions of Light Tanks and Armoured Cars, which may well have been mistaken for heavy armour from the air]
"In addition to the 120 tanks of the 105th Armored Brigade, the better part of another tank regiment appears to have been available to North Korea in late June" [elsewhere estimated to be about 100 tanks]. "[Additionlly] Thirty tanks reportedly joined the N.K. 7th (12th) Division at Inje in east central Korea just before it crossed the Parallel. This gave North Korea a total of 150 Russian-built T34 tanks in June 1950" [but there were other light tanks of soviet and possibly Japanese manufacture available as well....estimated total tank strength was close to 500 vehicles in my estimation] .
"In the six months before the invasion, a defensive-type army of 4 divisions and an armored regiment had doubled in strength to form 7 combat-ready divisions and an armored brigade." [these did not initially cross the border but they soon joioned the battle. by my estimation that adds a further 240 further tanks and an unknown number of other AFVs to the inventory]... And there were in addition 3 other newly activated and trained divisions, and 2 independent regiments [not sure how much armour, but some....say 50 AFVs] .
"The North Korean ground forces-the NKPA and the Border Constabulary-in June 1950 numbered about 135,000 men. This estimated total included 77,838 men in seven assault infantry divisions, 6,000 in the tank brigade, 3,000 in an independent infantry regiment, 2,000 in a motorcycle regiment, 23,000 in three reserve divisions, 18,600 in the Border Constabulary, and 5,000 in Army and I and II Corps Headquarters.
The North Korean infantry division at full strength numbered 11,000 men. It was a triangular division composed of three rifle regiments, each regiment having three battalions. [It was based on the Soviet WWII era Assault Rifle Division, which usually had an AC company attached and often an SU assault gun unit based around the SU-76 or similar attached] The division had as integral parts an artillery regiment
and a self-propelled gun battalion" [thats at least another 50 vehicles per Iassault Div, which adds at least 350 additional vehicles to the AFV inventory, pushing the total number of AFVs of all descriptions to well over 1000].
"There were also medical, signal, anti-tank, engineer, and training battalions [including Tank training units which I think were equipped with ex-Japanese equipment] , and reconnaissance and transport companies.
The artillery support of the North Korean division in 1950 closely resembled that of the older type of Soviet division in World War II. A division had 12 122-mm. howitzers, 24 76-mm. guns,
12 Su-76 self-propelled guns, 12 45-mm. antitank guns, and 36 14.5-mm. antitank rifles. In addition, the regiments and battalions had their own supporting weapons. Each regiment, for instance, had 6 120-mm. mortars, 4 76-mm. howitzers, and 6 45-mm. antitank guns. Each battalion had 9 82-mm. mortars, 2 45-mm. antitank guns, and 9 14.5-mm. antitank rifles. The companies had their own 61-mm. mortars. A North Korean rifle regiment at full strength numbered 2,794 men-204 officers, 711 noncommissioned officers, assault Infantry (of which there were seven divisions) had more vehicles....about 1879 compared to about 1100 for a regular 1945 style Infantry unit.
From the beginning the Soviet Union had been the sponsor for the NKPA and had provided it with the sinews of war. Most important at first were the Russian-built T34 tanks of the 105th Armored Brigade. The T34 was a standard medium tank in the Soviet Army at the end of World War II.
Other ordnance items supplied to the NKPA by the Soviets included 76-mm. and 122-mm. howitzers; 45-mm. guns; 76-mm. self-propelled guns; 45-mm. antitank guns; 61-mm., 82-mm., and 120-mm. mortars; small arms; ammunition for these weapons; and grenades. From the Soviet Union North Korea also received trucks, jeeps, radios, and fire control, signal, and medical equipment.
In the spring of 1950 the Soviet Union made particularly large shipments of arms and military supplies to North Korea. One captured North Korean supply officer stated that in May 1950, when he went to Ch'ongjin to get supplies for the N.K. 5th Division, Soviet merchant ships were unloading weapons and ammunition, and that trucks crowded the harbor waterfront area. Korean-speaking crew members told him the ships had come from Vladivostok. Markings on some of the North Korean equipment captured in the first few months of the Korean War show that it was manufactured in the Soviet Union in 1949-50 and, accordingly, could not have been materiel left behind in 1948 when the occupation forces withdrew from North Korea, as the Soviets have claimed.
North Korea began the war with about 180 aircraft, all supplied by Russia. Of these about 60 were YAK trainers; 40, YAK fighters; 70, attack bombers; and 10, reconnaissance planes".