Karl,
pm me if you are talking about the screws that mount the plate to the housing. The two cross-head screws are weird, but I found a pack some time back that are slightly too long. I have a few left over and I'd be glad to send you some. I don't even remember if I had to shorten them of use them as is, but know I replaced them in the tr6 and tr3.
jerry
I'm looking at #6-40 x 5/8 -they may not be exact, but they work.