As you know, I'm pretty good with identifying old parts but this one has me stumped.

I "think" it's MPC but it may also be Revell. It's molded in black and as you can see, I had to repair the spring. I didn't put much work into the repair as it won't show when installed up into it's slot anyway.

Here's how I lowered the back, Just ground out the crossmember from underneath and ground off the top, as I said, and the spring slides right up in. Just has to gring off the part of the spring that's showing so the floor would fit down onto the fender/frame properly.