The Airfix kit is a 1980 tooling, but still sharp and with some fine details. Fit is good too. I fixed a few things. The biggest issue is the weird stowage boxes on the chassis behind the cab, which have to go and be replaced with smaller boxes from scratch. I also aadded a 3d printed jerry can on each side.
If I make it deployed, I thought some fallschirmjager in Italy might make a more interesting crew. These are figures from Mars, in the dreaded soft plastic and they have enormous amounts of flash and seams. I've removed the worst, but there's still a lot more to be done.
The PAK 40 had some work done to refine the muzzle brake and improve the breech area but overall, its a very nice rendition, much better than the Matchbox attempt.
Apart from the muzzle brake, the gun benefits from thinning the lower front shield by about 50%, extending its support struts by about 2mm so it doesn't foul the main shield, adding the trail pivot pins, drilling out the gunsight eyepiece, filing out the recoil slide, adding the small shield below the recuperator and adding a groove around the gun shield to simulate the two layers.