Here's a bit of info on the Uruguay from a Uruguayan military site:
"Built in Stettin Germany by Vulcan in 1910 to Uruguayan specifications. It was incorporated in August of that year. This ship provided services for more than 40 years, requiring throughout all of them the fulfillment of the most varied and important activities, being the pride of the Country and the Navy.
Displacement 1400 tons; machines of 5,700 IHP; 25 knots; Carbon capacity 210 tons = 3,000 miles at 12 knots. Armament: Two 4.7" rapid-fire guns; four 12-pound TR, six machine guns and two 18" torpedo tubes, scrapped in 1953."
A bit of data about its role in the River Plate action:
"On December 13, 1939, while making an instructional trip with students of the Naval School, the torpedo boat cruiser "Uruguay" witnesses the combat between the battleship Graff Spee and the cruisers of the British community Ajax, Exeter and Achilles (Battle of the Río de la Plata).
Its Commander Captain Fernando Fuentes, based on these observations, and that part of the combat was taking place in Uruguayan jurisdictional waters, he set out to intercept the belligerents so at 7:00 p.d. while the Graf Spee was 12 miles from Punta del Este, and the Ajax 18 miles south of José Ignacio sounded the alarm again in the Graf Spee, this time it was the Uruguayan war cruiser "Uruguay" that left at the crossing of the Graf Spee to prevent it from sailing between the Island of Lobos and the coast, in addition to being located between the Graf Spee and the British cruisers so that they did not enter the Uruguayan coast in a very reckless action almost suicidal since any of the ships exceeded in firepower the old Cruiser of national flag, this action that later the German captain Langsdorff himself would declare his admiration for Captain Fuentes of the cruiser Uruguay that despite seeing the conflict and the power of the ships involved, he bravely stood in the way to protect Uruguayan rights in a determined act of exercise of national sovereignty.--
The "Uruguay" remained vigilant until seeing that the Graf Spee entered the Bay of Montevideo and in addition, double surveillance was ordered to search for possible castaways. She later moored near Flores Island and departed at dawn the next day heading east again to check that the ships left in the area were out of jurisdictional waters. Days later when the German battleship left the door to face its destination again the Cruiser Uruguay was waiting for it to escort it out of jurisdictional waters act that was not necessary since the German captain would order to fly his own ship when all his crew was evacuated."
From here:
Los cruceros de la Armada Nacional