1916 M101 backs
 

I've recently started collecting the M101 sets and have the chance to buy some cards with advertising backs. can anyone clue me in to the value of these backs as compared to a blank back or a non ad back ?

There are approximately 20 different backs. Some are more rare/valuable than others. They go anywhere from 1x value to 10x-25x value.....(a Gimbels variation rarely seen would be hotly contested).....

is there a consensus then as to which backs have what multipliers. For instance, Altoona Tribune backs , and Gimbels backs. Does card condition really matter when you are buying one of the ad backed cards ? The cards I am seeing are pretty beat up and would be considered Fair condition at best

I don't think there is a back multiplier chart anywhere. I have seen some super high prices on some scarce backs recently and some relatively low prices on others. You might be able to do a few board searches for rarity levels. I came close to finishing my back set (except for a few variations) many years ago. I think they are fun to collect. Those rarity levels have changed over time with new "discoveries" of certain ones.

thanks Leon. as usual you are a fountain of info !! :)