Hi Paul, I recently had a C grade circa 1893 re-done. In the process the gunsmith refinished this Parker using all the original components. Mine did have some barrel damage on the left, but he was able to repair. Looking at photos of yours, it may require new wood and small parts which will add to the cost. You can see before and after photos in the following thread.
http://parkerguns.org/forums/showthread.php?t=9317
The restoration on the C included stock refinishing and checkering, barrels re-worked, metal case coloring, and fine tuning fit and function. I would not fire this Parker without the re-work because of the left barrel. Cost was $2k. Yours would depend on how much you want to bring it back to original. Or, just make it functional. All depends on what you want the Parker for. I will advise you that refinishing to sell for a profit is not likely. Refinishing to use is very worthwhile.
Harry