1989 Platinum Day Date on eBay (18206)

[FTA]

Good morning. I have been looking at this 18206 on eBay for a while now. The seller seems legit (Swiss Watch Expo) and the only thing I can see wrong with the listing is that they claim it is a 1991-1992 watch but it is an L serial which seems to be more like 1989. I think they are stretching the truth so the watch doesn't sound quite so old. Anyway, the bracelet looks to be in ok shape considering it is about 30 years old, and I'm thinking of taking a leap. Here are my concerns: First, does the dial appear to be authentic? It has tritium dot markers on the outside and just about every 'roman' dial I've seen like this has no tritium markers. Next, I notice that it appears this exact watch was previously sold my Mid Town Watch in Manhattan (see second link). It does not say when it was sold, so it could have been last year, or could have been 5 years ago. In any event it just seems a little weird to me that the watch is back on the market again so soon. If anyone has any thoughts / comments on any of this -- or, ideally, know the history of this exact watch -- I'm all ears. Thanks.

PS:
I've been a member for years but have never posted before so TRF won't let me include links. If you go to eBay and enter 273914858637 in the search field you will see the watch I'm talking about (273914858637 is the ebay item number). Also if you go to midtownwatch dot com and enter 18206 in the search field you will see what appears to be this exact same watch as a sold item. Thanks again and sorry for the extra leg work!