The kit dates back to 1970, and shows it. The Mk1 was the original kit, which has been re-released a number of times over the years, with the MkV being the same basic kit, with additional parts to make the MkV - of sorts.
With a lot of care and attention, it can be made into a reasonable model, but overall fit of parts is not as good as it should be, due to the age of the moulds.
I bought the 1/24th scale Bf109E some years ago, as it was dramatically reduced in price, from the (then) £30 retail, down to £7 !!
I ended up building it as a belly-landed example, as not only did some important parts not fit well, but the undercarriage legs were poorly moulded. A friend bought the so-called MkV version of the Spit, and has 'put it aside' due to frustration because of poor fit of parts.
That said, it can be built into a nice model, but might not be a good choice as something to share with a young son, and the same goes for all of the old Airfix 1/24th scale kits. Personally, if it's now priced at £60, I think it's over-priced, and there are better choices for the same, or less, money.
I haven't built the trumpeter 1/24th scale kits, and I believe there are some inaccurate areas, but they might be a better choice for ease of building, or, if you can find one (perhaps on e-bay), the 1/32nd scale Hasegawa Spitfire MkV is excellent. Or there's the Trumpeter or Hobby Boss in the same scale.
Hope this helps.