Not a correction, it enables a Mk I to be built as a Mk IIa. Already well covered I am afraid. Airfix have this covered in both 1/72 and 1/48. Ultracast have had a conversion for a long time and more recently 3D-Kits have been selling conversion kits in 1/72 and 1/48 with or without decals. Still, it looks very good quality and I would certainly give it consideration for converting the Tamiya kit. You can also make a Mk IIb but need to take the oil cooler with the round aperture and wings from the Mk Vb kit but use the fabric ailerons from the Mk I. The Mk I wings with the metal ailerons and D shaped oil cooler can then be used with the Mk V kit to make a Mk Va. Some Mk Vs also had Coffman bulges and Rotol spinners. 315 squadron's AB931/PK*C was one. It featured in one of Montex's mask sets. The conversion would be ideal for that. Tip. The Airfix 1/72 Spitfire MK I early/Mk IIa kit comprises the Mk I with an extra sprue with Rotol spinner, Coffman bulge, Watts propeller, pole aerial and an oil cooler with a round aperture. You can build both options by just buying a Mk I kit as well so saving a £ or £2, and you still have a round oil cooler which you can use for a Mk Va.