dd051,
Having pipes professionally restored (even just cleaned and reamed) can be very pricey. Since you say that these were "working pipes" I'm assuming that you may not want to invest a fortune in them. You might try reaming them out yourself unless they have thin walls. It's not that hard, just takes a little patience.
My favorite reamer is the Senior brand, an adaptation of the old Kleen 'n Reem, but it takes some practice to learn to use it well and is probably not the best tool for this project. I'd recommend a T-handled set of reamers. You'll see them under a variety of brand names (Castleford, Brebbia, etc.) but all are the same. The have a T-shaped handle which can hold any of the 4 different diameter reamers.
Start with the smallest one, if it will go in the chamber completely, ignore it and move up to the next bigger size. Before actually reaming, make sure the insert is completely seated in the handle so that you don't crack the handle. Start out slowly and don't put too much pressure on the reamer. Put more pressure on the side with the thick cake but keep the tool straight up-and-down so that the cutting surfaces stay parallel to the chamber walls. When you get to the bottom, move up to the next bigger size if necessary and repeat.
As Kevin mentioned, it's best not to go down to bare wood. But if you do it's not a particularly great tragedy. ALL briar pipes started out as bare wood. Just make sure that the chamber is reamed out evenly otherwise you will develop hot spots in the bowl and it may burn out. Treat it as you would a brand new pipe and break it in as you normally would. If the first pipe turns out well, move on to the next.
Pipesandcigars.com carries both the Senior Reamer and the T-handle. They're nice folks to deal with and have a wide selection of tobacco at excellent prices. You'll see their link in orange at the bottom left corner of the page under Sponsor Links.
Good luck