If you're looking for a 1/72 Yak-7, you should also consider the Valom series of Yak-7's, which were, let's say, "inspired by" the Dakoplast/Modelist kit, with improvements. Each of the different Valom ones includes the same basic Valom (not Dakoplast) kit with decals and in some cases resin parts customized for the specific boxing (Yak-7A, -7B, -7B (late version), -7V, -7PVRD; maybe a UTI, too). The Yak-7b (late version) (72040) has an additional fuselage for the bubble-canopy late Yak-7, although all it lacks to build it as any of the earlier types is the early canopy. In other words, if you can find any of them for a good price, buy it. The Valom kits were expensive when they first came out, but could sometimes be found being sold off at reduced prices. I don't think the kits sold well; when I asked Vaclav Lomitzki (Mr Valom) about the possibility he might release a Yak-1b, he said "No!"; I got the impression he would never do another Yak again, sad to say...
I hope the above is clear enough, but let me know if you want more specific details.
John
I've been working (on and off) on the late Yak-7B from Valom for the last 6 months or so. To put it short: it is not a straightforward built if you want to replicate a good-looking airplane. The plastic requires a lot of thinning around the cockpit and wing edges. Main gear wells need complete scratch- reconstruction. The landing gears from the kit are going straight to the trash. Wing root intakes simply do not exist (which could be a good thing-if you want to make different versions:)). Resin cockpit details are full of inaccuracies, so I ended up using just a few bits of them, while scratchbuilding entire interior. I did not have a chance to see the Modelist kit, but it could be a better option for the money.
Good luck, and a lot of patience to all VVS aficionados!
Boris.