We stock the drive types that actually show up on these jobs - chain, belt, and screw-drive heads, plus standard safety sensor kits for houses still running on the older reversal hardware. What we don't carry on the truck is every manufacturer's proprietary circuit board; if your unit needs a specific board rather than a full head replacement, that can mean a short wait on the part.
For a stuck job between a repair and a full swap, our honest answer: if the motor and logic board are both original to a 1960s-era house, we'll usually recommend replacement over chasing parts for a unit that old. It's a straight call, not a hard sell - see the Scranton opener installation page for the full rundown of what we install across the area.