Need advice: Speedmaster 145.022-69 with DON bezel - buy it or leave it?

First of all, a very heartfelt hello from Munich to all of you.
I have been around reading and learning for more than a year now, as I have started collecting only in 2015...
Love this forum and the wealth of knowledge and helpfulness I have seen so far.

To be honest, I have a big bunch of questions for you, as I am safeguard to own a few vintage Omegas for my children (my weakness are 33.3.s from the 30/40s, an Aviator from the 30s a.o. and Speedmasters from the 60s).
For time reasons I'd like to start though with a request for advice of buy it or leave it.

We are talking about a SpM 145.022-69 with a DON bezel from 1970 (Serial 2911...) offered by a local pawn shop.
IMHO, there are PROs (DON bezel) and CONs (condition) - I do have a talented watchmaker tough who could fix various damages... So my three main questions would be:

1. I am confused about the caliber case - my other 145.022-69 (DNN) does not have this "inner ring" with a kind of thread (marked on pic below). What is the function of this ring? AND, are the damages visible on the ring a major problem?
2. Any other inconsistencies you might have spotted?
3. Would you buy it for € 4000 (4500 USD)?

Thank you VERY much in advance for your help!

I think this ring is some kind of replacement for dust cover.
Watch looks nice and price is fair.
DON is also in fair condition..

Chocolate dialed 69er with a decent don for $4.5k ... better hope its still there ...

Edit : VAP @ $4.5k, thats what...the bezel and the midcase (if unpolished)?

run back to them as fast as you can and throw the money at them

Do this asap

I tend to second Al here. A chocolate dial remains attractive till you eventually realize it's been glued to the movement by the master butchmaker who cared of the watch 😗

something tells me you'll be into it for A LOT more after all the work that is needed to repair it, as long as you're willing to to take that risk, proceed. personally, I'd pass, but that's because I don't particularly fancy chocolate dials, and I like examples that don't come day 1 with so many issues.

@all: thank you loads for your thoughts. I am glad to read that my instinct seems to work and that my concerns are mirrored by some of you. I have decided to take the risk and I just confirmed my intention to buy it. Not sure, if I look forward to listen to my watchmaker's lections once we sit down to take a close look, but I hope for the best. Will share a better pic, once we have fixed the expected issues...