I have 2 types of camelbacks for 12", 18", 24", 36", 48", 60" and 72". The HK series is without a 45 deg. angle, used on lathe beds and the HKA series are with a 45 deg angle used on milling machines with dovetails. I have a few used prisms too. What size SE are you looking for? I see on Facebook Market Place several used granite plates. Facebook has taken over for Craigslist it seems. You can email me for more info:
[email protected]
I see on eBay there is a used 24 x 36" plate in Walker LA....for $300.00
MOJAVE GRANITE PLATE 24 X 36 X 4.5 | eBay