Been a long while since I last posted here but I have need for a part to a Westinghouse OV-50.  The part in question is also used on OV 25s and is to allow the OV25 and OV 50 to be used on 1-1/4" pipe.  It's a casting that fits in between the two slipfitter clamps and is held in place with two screws.  There is one on my "transitional" OV-25, you just have to magnify it to get a better look.

I have a few really crappy OV-25's that are most likely gonna get parted out. I'll try and look this weekend and see if any of them have the part you're looking for .