Tom,
We had the Don Edmunds/Pete Brock "Lang-Cooper" for restoration at Bryan's shop a few years ago. The frame was also cracked just about everywhere! Nothing that a few reinforcing steel-sheet bits cannot fix!
The K&B McLaren MkII is an oddity in the slot car collecting world. It used a unique chassis, a K&B "Super Challenger" motor made for K&B and Aurora in Japan, used a stressed member, and that pretty body with very accurate decals. The Charlie Hayes "signed" tray was nice too!
The car did not run too badly but its engineering was already obsolete when it came out. Here is the "regular" version: