MG T-ABC

I somehow failed to note what screws were holding my firewall (scuttle) to the timber wood. I see hex heads in my pictures. Is that correct? Can anyone advise the size, length and type screw?

There are 20 oval holes for them in my firewall. Some are pretty close together, as if there was some other purpose for them. Are all 20 holes used just to hold the firewall to the wood? Or are two used for something else?

Well, I think I can answer my own question.
I found my old screws at the bottom of a box of junk parts, and they are 5/16-22 BSF x 2-3/4" long with hex nuts, flat washers and a lock washer, and only 18 of them.
Two of them on the right side hold the steering column support. Near as I can guess, there are two on the left side that are a mirror image of the two on the right for the steering column, as if there had been planning for a LHD version, so they must be a mistake by the punch press die set maker and simply not used.

That sounds right. I pulled hex bolts out of a basket case, which I assumed were the original parts.