You are building an injected foam plane right???? I have not built the Zero, just the Spit, (4) 1/2a Cubs, (1) 25 sized Cub, (2) 25 sized Cessna's, P-39. On the Cessna's you spread epoxy all over the inside opf the fire wall/engine compartment and the ply wood fire wall slide into molded grooves. The Spit had a fire wall and beams that you epoxyed into place. It was a long time ago but I may have mixed up the planes here.

There has to be some one on here that has built the Zero that really knows how it went together.

Dru.