That concrete bench is out at the Tucson Rifle Club near 3 pts Az on their 500M silhouette range. It is quite old, a bit low and some rock till you wedge something under a corner. But it is heavy. They are supposed to make new ones one of these years.
I have the non bedding block Bobby Hart LRT with a SA Rem 700. Used same action screws. The cheek weld is perfect even with the higher picatinny and a 50mm scope. When shooting it off a front rest the stock does sit a bit higher. Have had to use a thicker rear bag. When a shorty Harris bi-pod is used there is no issue.
I bought one with no block (a lefty) LA. I had a rebarrel in the works, so just slapped the 700 in there. The little barrel looked funny but it shot as good or better than the stock it came out of. since the rebarrel (Brux #8) I had to open up the channel and haven't bedded it yet. but I do have the stuff, just got my clay puddy yesterday. Still shoots good with 3 different bullets grouping at .65 or under. 7RM. the stock is comfortable except for a huge grip. it is pretty bulky, great for recoil and scope height but I won't be packing it anywhere long or steep. outside finish VG. and I think I just had to sand some inletting a touch for bottom metal for the inital fit.