I do not repair or restore pens for customers. I only repair and restore pens I sell. I can perform most repairs and restoration but do send out some of the more complicated repairs to experts. There are many very good pen repairmen in the USA. Here is a list of some I highly recommend. This is by no means comprehensive and if someone is not on the list it's not because they are not good. I just don't have experience with them. In addition, I listed a few links to parts and pen tool dealers in case you're a DYI type.
Pentiques.com - Aaron and Kim Svabik are really nice people. Aaron does fantastic work, can do most repairs, has a fast turnaround time, and excellent rates. Pen repairman are notorious for keeping your pen for weeks or months, but Aaron's turnaround in measured in days. Fast service without compromising quality, and Kim to keep him in line.
Martin's Pens 51 - Martin Ferguson is a great guy. He does fantastic work and is a fountain of knowledge who is always willing to give friendly advise. His specialty is Parker and Sheaffer pens, especially Sheaffer Snorkels and Parker Vacumatics. He attends most pen shows as well.
Main Street Pens - Ron Zorn is a good guy. He's been repairing pens since 1990, making him one of the veterans of pen repair, and there isn't much he hasn't seen before. He can handle some pretty complicated repairs like new ends on Waterman Hundred Year pens. He's attends quite a few pen shows and is also the President of The Pen Collectors of America
Inkpen - Inkpen is owned by two of the nicest people in the pen community; Joel Hamilton and Sherrell Tyree. They can repair most vintage fountain pens and have fast and very friendly service
Mike-it-Work Nib Repair - Mike Masuyama does nothing but nib repair and modification and it keeps him very busy. There are not very many nibmeisters out there but Mike is one of the best. He attends quite a few pen shows as well
Pen Sac Company - This is the best place to get pen sacs in quantity. They have almost all sizes and they make the sacs here in the USA on original 1925 equipment. Very good quality sacs. They are old school. You have to print the order form and mail it in. Not great if you're in a hurry but they do ship quickly once they get the order.
Pentooling.com - Pentooling.com is one of the best places to find pen repair tools, hard to find parts and just about anything you need to repair or restore your pens
Pendemonium - Pendemonium is owned by the Queen of Pendom, Sam and her husband Frank. They specialize in all the weird and wonderful oddities of the pen world as well as pens, parts, ephemera and a lot of stuff you cannot get anywhere else. They are an especially good source for anything Sheaffer related. They also attend many pen shows.