The owner actually cut the seat tube off before bringing it to me to see if lowering the seat would be sufficient. She also drilled the holes with the intent of pinning the post at the correct height, but stopped short of drilling the post.
Since I have no torches or brazing experience, tig welding is my only option. That is one reason for putting it on the front of the seat tube. If I were to put it on the rear, I would have to lower it a fair amount to give myself room to work. That would not be a problem in itself, as the seat post is 12-3/4" long, but the farther down the tube I go the harder it is to clean up the weld. Once I get the clamp tube removed and cleaned up I will decide which location works for me. I don't think putting it on the front side would create an obstruction.
I'd like to thank You all for the sound advice you have given me so far.