Who drills front brake drums????

Don't think "quick", but "less total effort", since you should have plenty of other things to fool with on your car. If your drums are 10", you can sell the whole setup to someone with 9" drums (spindle, hub, drum, UCA).

Most people have the opposite problem, i.e. they converted to BBP front disks and want their rear to match. Sounds like an opportune time for you to convert to 73+ front disks, and many posts on that. Until you collect parts, just carry 2 spares in the trunk.