The Diecast Encyclopedia is not clear on what happened to many of the the Matchbox castings once they came into Universal's ownership. It would seem most likely that the Matchbox Fire Engine mold tooling ended up at MC Toy (Maisto) eventually!
That's possible. Other that the details that were part of the base on the MBX version being part of the body on the Maisto version, the big difference I see between the two is in the A pillars. The Maisto version is more upright than the MBX one. There are several other Maisto models that look like Matchbox castings, though. It does seem possible that some of the tooling made its way to MC at some point!
Very true. And one of the responses I share back with others is that many companies also had access to the same vehicle others copied from real life too! We also dont know how many tool revisions have occurred due to breakage and wear in the decades between when the Matchbox was cast and the one the Maisto from above was made.
Just speculation on my part but it seems the front bumper of the base plate and front roof line on the body would be the most likely weaker (if solid steel plate, can be weak) points on the mold or die portion of the tooling. From what I have seen of mold tools though - those would be where the thinnest portion of them would be.