It’s pretty obvious that you have made up your mind. They’re your guns, shoot them if you like. (It’s also your face behind the bolt, so, again, shoot them if you like.) IMO being contemptuous of the advice people have given is not charitable, “not particularly high road,” as they say in these parts, since they are not trying to trash your guns, they’re just giving you their experienced opinions as to what some marks may mean, and that it might be bad news in terms of potential safety risks. You may disagree but don’t ridicule, please.
I don’t know Brian Dick or any other Enfield smith, but I can tell you that the Enfield is a lot more esoteric in terms of parts fitting, etc compared to Mausers and Springfields, and my guess is, this guy gets the nod from those who are enthusiasts about these guns, because he has experience and specialization, and because he has a set of the gauges necessary to actually diagnose these things, and the knowledge to use them, which your average gun plumber does not.
I think the potential safety risks of non-matching bolts in Enfield circles might be a bit overblown…. But to me it’s not worth the risk of the gun beating itself up, so I only buy ones that match. The price difference isn’t huge if you’re patient. Some rifles were condemned to DP purely because they needed training guns… but others were condemned for very real safety reasons. With hundreds of thousands of good ones available it’s worth asking if the risk is worth taking.
If they were my rifles and there was question about markings etc I’d throw them on Gunbroker with full photos of the marks and disclosure of suspicions, range trip, gunsmith, etc. and let them bring what they bring …but that’s just me.
That all being said, the good news all around is, .303 Brit is now relatively expensive so a “shooter” rifle, matching, mismatched, potentially condemned, or no, will probably only have a few dozen rounds put through it in a lifetime now, not hundreds at a time from a spam can of surplus ammo. So these concerns are probably less serious than they were a couple of decades ago, when an old rifle could be expected to hit the range often and be abused compared to today.