I do not understand all the hand ringing, let's see if I can sum this up somewhat correctly.
So far as I know, originally, there were only two water pump setups and matching two balancer timing mark/ scale setups
Either you had the older (pre??69 or 70?) setup with the rad outlet on the driver side and the timing scale on the passenger side, or you had a later car with the opposite.
ADDITIONALLY there is the possibility that the balancer ring has slipped, and regardless of what it was supposed to be, it might now be wrong, OR someone swapped wrong balancers, either OEM or aftermarket
So choose a setup, and if what you last had has a good set of aligned pulleys, I'd seriously consider staying with that.
THEN worry about timing. You don't really NEED a timing scale. You can MAKE a timing pointer and MARK your flywheel so that you can time it up to "into the 50's" for checking both mechanical and vacuum advance.
So use a piston stop to check TDC accuracy, or even start over to establish such. Then degree the balancer Accurately measure the circumference with a thin tape and double check. Then figure the degrees per inch from that. I've only done about 4. I start by figuring how much 20 degrees is. You cannot make the initial distance measurement with dividers, you must use a tape. So now assuming you chose 20, you have two marks, your original TDC if it was correct, or the new TDC, and the new 20 mark.
Now take dividers and set them to the distance of the two marks, and extend that out so you have 40 and 60.
Next, "fiddle" the dividers until you have half, AKA 10 degrees. Now mark that in, and you can double check it by going both ways, AKA from TDC to 10 and from 20 back to 10 and they should match
Next, after double checking the 10 marks, fiddle the dividers down to 5 and do that. Use a small square device and a scribe, and then if you want, pull the balancer for ease, and use a triangle file to carefully deepen them.
A number stamp is handy to at least mark, say, 20 and 40, etc.
This is just not that hard. The first balancer I did was a 440 back in 1972 or so, and I had no internet to guide the way
