Vintage Speedmaster 321 - Help before purchase

Hi there,

Newbie from NYC, reaching out for advice.

I've been avidly reading through the forum and other blogs to educate myself on vintage Speedmasters. I currently own a late 90's Pro and an late 80's reduced but am mostly a complete newbie to watch collecting. I have recently set my mind on acquiring a nice vintage 321 for a reasonable price.

So I actually won one on eBay this Friday (link pasted below), and would love to get some expert opinion before going through with this.

I have no doubt in my mind the red chrono hand is an add on, since even the seller never mentions it, and the serial doesn't match the range for a genuine ultraman. But I love the look and am perfectly fine knowing this.

Mostly everything else I could tell from the pictures seemed right. Bezel and dial seem right, so does the movement and case back. The hands look a bit too white and a little short and may be service pieces, but I think I could live with that or eventually source accurate ones to replace them. Crystal doesn't appear to be signed but this too i can live with.

Overall, I find the watch very attractive and desirable, condition seems to be good or better, and it's stated as recently serviced and running correctly. The seller is based in Brazil, his reviews are good and he seems to sell genuine collectable watches regularly.

I have a lot of experience buying on eBay but little when it comes to watches, so I'd really appreciate help looking at the photos and description to be aware of any major red flags and get some opinions on value for the price.

Here's the link to watch: https://www.ebay.com/itm/312843391544

Many thanks in advance to those willing to help me navigate this!

+1 on the above

Firstly, you should've asked this before budding. You won the auction and should complete the purchase.

Regarding the watch, it seems very meh. The dial is very average with unattractive, partially absent plots, and the main colour of the dial looks a bit dry. The bezel is average.
My main concern is the case. It may be the angles and lighting but it looks very wrong to me as if it's been completely refinished in a poor manner.
All of the above and the location is why it sold so cheap.