I run a large collision shop.....
Are you the only one working in your "large collision shop"? Do you have people to answer phone calls? Emails? Do you have a receptionist to take payments, pay the bills and order supplies? Do you have a bunch of guys working on cars while you're making calls?
Now imagine you're the only one running the shop, who has to order supplies, process payments, process orders, talk to customers on the phone (while you're trying to get someone else's order done!), answer emails AND do the actual work. Can you type emails while you're doing body work? Talk on the phone while you're pounding out a dent? Do you think you'd ever get your head above water? If you were going to cut yourself some slack somewhere, where do you think you'd start?
Besides, people typically need their car back yesterday. Revolver work is usually a little less urgent.
Case in point. In 2013, I had a customer place what was for me a relatively large order. A cartridge belt, two cartridge slides and four holsters. After a bit, I realized I was spending as much time responding to emails, answering his questions, doing research and helping him make up his mind than it was going to take to actually make the stuff. Which basically cuts my already dismal hourly rate in half, or less. I had to just stop answering his emails until I could get his rig done. No way around it. This is a part-time, after-hours venture for me anyway, so it's not like I'm cranking out several holsters a day. Couple weeks go by, his rig is 75% completed and he cancels the order. Not only was I out the many hours spent communicating but the hours spent at the work bench, materials and the cost of several ugly conchos he wanted. All while I was right smack in the middle of a home construction project that took way more of my time than I expected. Sometimes supplies come into short supply without warning. Sometimes folks like my cartridge conversion guy have unforeseen health problems. So yeah, you might understand how difficult it is to estimate lead time and answer every email from every impatient customer AND get the job done.
My advice to the OP, leave him alone and let him do his job. I assure you, he doesn't want to keep your gun any longer than he has to and I'm sure he doesn't need a daily reminder of what is yet on his plate. You're going to do what I did with one of my custom Rugers. I got so worked up because the gripmaker took way more time than he estimated
and it ruined the whole thing for me. Hindsight, I should've taken the advice I'm giving you here. Relax, be patient, you'll have a more harmonious outcome.