Personally I would not reblue an antique firearm unless it was going to be a wall hanger they lose all collector value.
if it has sentimental value then do it to honor who used it before just don't think the reblue will increase the value to even cover the re blue charge. That said Highsmith in greenfield does a nice job and has a portfolio in the shop of the work they do. I had them do a colt 1911 for me and they did a great job.