GeorgeG;
I have looked at a few M52's.
Owned three, a M52-1 and two M52-2's.
I currently own just the one, M52-1 that I shoot for Bullseye centerfire.
They are all fine firearms and very accurate in the right hands but very unforgiving on the days you are not totally focused
I looked at all three pic's of your barrel and even magnified them.
I would venture to guess that it came from the factory like that.
Reasoning is that it does not interfere at all with the function of the pistol, period.
The last M52-2 that I owned was missing the dimple on the bottom of the dust cover to hold the weight on in position.
S&W said "there was no design change that we note, so it must have been missed during the manufacturing process".
Shot fantastic with or without that dimple
The ramp looks fine, to me.
I wish you could fire it,(I know some inspection periods do not allow you to fire it, but...) but hand cycling a slide with dummy ammo or just empty casings or whatever does not in any way make a conclusion of how it will operate when live ammunition is used...ie...how are you cycling it by hand, fast, slow, hard, soft, etc...
I do not know the price, but firing it for a function test would be the bottom line.
I personally never fired any of mine prior to purchase and they always functioned as they should.
It is the chance you take.
Good luck.
By the way, are you using factory magazines with the steel follower.(the ones made a while ago and not the ones for sale by S&W currently ?)
Wolff makes a spring kit with a factory 8# recoil spring and a firing pin spring.
Something to consider if you buy it.
By the way, unless you are good with smithing, do not try and replace the firing pin spring yourself.(it is a little touchy, if you know what I mean).
Clarence