Bearing retainers are considered uncool because lots of low end bikes had them for manufacturing ease, but especially in a 75 bb I don't think they're a problem. They make it a lot easier to service the bottom bracket, and while one extra ball is theoretically slightly better, it doesn't really work that way in practice and even the theoretical gains are minuscule. If you need to replace the bearings you just poke out the old ones with some small tool or your bare hands and put in new 1/4" bearings.

However, if your BB had play in it, you don't need new bearings, you need to learn to adjust your BB, as it's probably simply loose. If achieving a proper adjustment is impossible, then the bearings may be at fault, though it's more likely that the cups are worn than the bearings. Replacing the bearings would be more something you'd do during periodic maintenance. Also, replacing the bearings in free ball setups is really something people do more because it's cheap and easy than because it's really all that necessary.