Here's a new resource for fellow Bottleheads and DIYers.
You might have seen Horace Atkinson's products on James Carroll's site. It turns out he carries a full line of aluminum transformer covers. It seems that he can get nearly any size you would possibly need. A cover for a Foreplay transformer goes for about $20 ($25 if you want it polished up to a nice shine) + shipping. The one in the photo below has been potted (he offers that service too) and that's why you don't see any mounting screws. He does supply mounting brackets and screws to bolt yours down to the chassis.
If you are looking for a specific size just drop Horace a line and he will give you a quote. I'm looking for a pair to fit the Hammond 125ESE OPTs. It looks like they will cost $23 each unpolished, $5 more for the shiny stuff.
Another product for the DIYer-custom terminal boards.
I should point out that I have no business relationship or agreement with Horace. I felt that there might be some interest in the products he carries and have had a few inquiries from fellow Bottleheads regarding a source for covers to fit the Foreplay power transformer.