What I was told by Francisco at M&R's Preventative Maintenance course was that pretty much everything can be repaired except for an unevenly worn center shaft and/or carousel. Just make sure those presses start level and lubed, stay level and lubed, keep your air dry and they will just keep going for practically forever with the occasional repair here and there...some more heroic than others...like snaking all new air lines through the arms...or replacing a lift cylinder on a Gauntlet Z 12/14.