I had Nathan build me a 338-06 back in 2016, and I was really pleased with how it all went, and the rifle shoots extremely well. However, my friend had a completely different experience. It started out good, but then Nathan wouldn't return his calls. My friend began to get worried because he was working on a Wetherby MK V he had sent him. I felt bad for recommending Nathan. I called and emailed Nathan a bunch of times, and he eventually replied to my friend. The rifle looked good in the pics that were sent, however, after receiving the rifle my friend discovered that that it was all messed up. I can't remember all the details but it wasn't good. I do know that another smith had to fix things, and they even had to replace the stock. My friend was super mad and confronted Nathan. He ended up refunding my friend some money, at least enough to cover the cost of the replacement stock. Nathan obviously knew he had screwed up. The whole thing left a bad taste in my mouth, and I still get crap from the guys in camp for recommended Nathan.
I would call the ATF if Nathan has your money and won't respond.