their being off face is not a big problem, it can be repaired. A more important check is the condition of the barrels in terms of rust, pitting, and minimum wall thickness. If the barrels are good that is a good foundation. So check the barrels out in detail and if you do not have the tools or experience to judge locate a good gunsmith who understands old double guns to evaluate the guns.
Once barrels check out, look at the stock dimensions, can you shoot them as is or will they need alteration or replacement. Replacement can get deadly in terms of thousands to have it done right.
I will not go further as I am sure others will, but those are the first two things I would look at
