What is your opinion on this Heuer 1550SG “Bundeswehr” Chronograph, I have some concerns about?

A friend of me. Fell in love with a Heuer 1550SG “Bundeswehr” Chronograph. And is seriously thinking of buying the next watch.
But I have a few concerns.

One is the fact the caseback looks like it has seen a grinder. My main thougth is what does someone have to hide?

The crystal has a lot of clearance from the bezel. Is this a correct crystal?

Is the crown original? It is unmarked.

The movement seems to have no Heuer logo or other distinctive inscription. I do not know if it should.

The rest seems legit to me.
But I have absolutely no significant knowledge of vintage Heuer, and I hope to find an experts opinion on this particular watch.
Now the pictures:

Hi-it's an easy watch to fall in love with!
In my opinion, it looks fine overall. The movement wouldn't normally be signed. The crystal is not original-although there are some available these days for replacement, the condition looks good overall. The caseback is peculiar I will admit, however a lot went on with these watches over the years with caseback changes and re-etching, however I don't recall seeing one ground away like that-nor can I think of why it would have been done. Some buyers would insist on a marked caseback so it can have a bearing on the resale value.
I hope that helps!
Steve

As Steve says all looks good. The caseback could have had an enscription to someone on it that a later owner didn’t want on it. First time I’ve seen a caseback ground away quite this way.

I thought I’d heard before that Sinn service these without issue and have plenty of spares for them, so a crystal and caseback could be an option from them.

The Bund is a sweet watch and one I want in the collection at some point.