As an apprentice, I'm not sure of the finer points of tap rules, but using 750kcmil, it doesn't look like a large enough box to accomodate the bends shown to satisfy code
Joe: Judging by the appearance, this is an "oldie"... We run into a lot of these in the older buildings. It seems to me that "back then" whatever you could fit into an enclosure was "OK". Bless the guy who did it.
Like the "old timers" used to tell me.... "that's when 'lectricians earned there money!!" Rigid pipe, rubber & cloth wire, etc. John