My 75 Finally Gets The Attention It Deserves(This Could Take a While)

I have a couple of quick questions. First, the drivers side exhaust manifold heat shroud has two small holes in the upper surface that would have been where the inner shield attached. Did all manifolds with this configuration use that inner shield? I don't have one and I'm wondering if it's yet another piece I need to track down, or can I braze them shut and be done with it? While we're at it, what was its purpose? It doesn't look like it would help direct warm air to the air cleaner inlet, so was it there to protect plug wires?

Second question, after sitting for thirty five years my three speed transmission is at a shop getting a look over. I also have a four speed back in L.A. that I bought years ago and never got around to installing. Is it an easy task to switch from a three to a four speed, or a major undertaking? I'd imagine there are some additional parts I'd have to track down, but I've never look into it enough to know what I'm up against.