I too have gone through 2 of the repro batteries trying to keep my car looking somewhat authentic, the last one finally died......so we would use a common battery to start the car, then put the dead repro in at shows.....
I got tired of that and am NOT showing in MCA classes anymore, so I just recently bought the "Better/Best" topper that is on the market, and an EXCIDE battery group 24F in, of all places HOME DEPOT!!
IT HAS the gusset for the original '65 style hold-down bracket!!
I cut off the fabric carry strap, peeled all the stickers off of it, put it in, put the topper on it, hooked it up, and NEVER in 7 years have had the engine turn over so fast!!
40 month FREE REPLACEMENT!!