There will be a mixture of materials in the subframe. I imagen finished article will be mainly t45. Just on with a quick sketch of a catch tank tonight first 5 mins I have had to myself this weekend. Looking at catch tank / expansion tank possibly a gearbox breather which will double up as a remote filler. Here will be the an10 breather tank which, wil use a breathable cap so is an enclosed unit. I will be making 1 as a prototype to start with.