I had some similar issues that I posted extensively about on the 1911forum sight....
I posted some photos and some accurate measurements (the left side of the pic should read .047" and not .47")...
Like the OP, I purchased on line.... both because no one local stocked what I wanted and because the guys prices (on everything he sold) were the lowest to be found anywhere. I had a heads up about the off center issue and asked him to post add'l pics of the muzzle. I posted the pics here for review, and though most said it looked good, it looked as if it might be just a touch off center. I rolled the dice and bought it.
Mine looks just about like yours does.... and on mine the difference in wall thickness is ~.027", which would imply that the hole is off center by ~.014".
Being 'wanna be' machinist myself, and having had to design and tolerance a few machined parts as part of my work, it helps to appreciate that this offset, though be it larger than what I would want and expect, is not really a gross discrepancy.
Indeed, without a way to reference the bore axis of the barrel to the recoil spring cut, it's difficult to ascertain whether the recoil spring hole is off, or whether the grinding and and finishing operations took more material off one side than the other.
I think the discrepancy is actually a combination of both.
I corresponded with two different guys who had similar problems via. p.m. One had a much larger discrepancy than I, sent it back to Colt and received his pistol back 4 weeks later with a new slide fitted to it. The other guy said his looked just like mine and when he sent it back to Colt they returned it to him saying it was within their tolerance.
I called Colt and the customer service gal was great. Unfortunately, their policy (which though I understand, I don't like) is that they must receive the gun in hand to make any evaluation. They would not assess it based on my photos and measurements. So they sent me a call tag to ship it into them free of charge.
But the more I investigated and read up on people returning guns for service (not just Colts either) I came to realize that letting the gun out of your control is not without risk. Some people received their guns back with scratches, or worse yet, new problems.
Also, I was told that if Colt repairs a problem, the round trip shipping is on them. But if they determine that there is no problem, you'll have to pick up the bill. Yet another element of risk added to the prospect of returning the gun for service.
Anther guy challenged me that had I not read up on this issue on the gun boards, I may well have never noticed it at all and been a happy camper for years to come. I can't say for sure, but I he may be right.
So I decided to test the gun myself and found it to be 100% reliable in every way, as well as very accurate and with a great trigger. This evaluation added a lot of much needed info. to my decision. The gun was exceeding all of my performance expectations, and I concluded that the cosmetic flaw was minor. Let's say I"m satisfied with my decision. I'm not 100% happy about it, but I decided that the risk of sending it back is greater than the possible benefit of getting a prettier slide. And in hindsight, if I had handled this Colt at a gun store and the owner said "I'll knock $75 off because of the recoil spring hole issue" I suspect I would have plopped my money down.
Your situation is different than mine, however, in that you have an add'l problem with your safety that is definitely not cosmetic in nature. Have you checked to see if the spring detent is hung up on a burr or something?
Colt will certainly (imo) pay for the round trip to make your safety problem right. And they may fit a knew slide for you as well. So I think you're best bet is to send it back to Colt.
