Have I bought a turkey of a vintage Seamaster?!

It was me. And I rather agree with your thoughts about the site and the owner. I only linked it to save me regurgitating all of the DS&S info.

I would not buy from there.

It’s not a collector’s piece, but the bracelet is nice and the watch has the early-60s panache you might have been going for in the first place. The fact that watches of that era got polished to hell and—at the manufacturer’s urging—had their parts swapped out with abandon is a big part of the reason that unmolested pieces are desired by collectors now. I grant you permission to wear and enjoy your watch while you study up in preparation of getting a reasonably priced vintage Seamaster that you’ll love. They are absolutely out there.

Ahhh.. don’t sweat it. You’ve paid your noob tax. We all have. I would wear the watch and not invest another penny into it. Save up for a collector grade piece and read the “learn how to fish” thread.

I would agree with this other than I think the OP said the crystal was loose, which is not good. I would at least get a correct crystal into it

Missed that. Service is of course worthwhile.

Just because it is not a collector item it doesn't mean you can't love it and enjoy it. Things degrade, people fix them. Not everyone likes them degraded.

If you like it, it's a fun watch to have and enjoy. If you "want" a collector item then...this is not it.

I think this is an important note for the OP. Redials are not all a viscous conspiracy of crooked sellers trying to defraud unsuspecting buyers (there are some of those). It was common practice back in the day (and currently actually if a fresh factory dial isn’t available from the manufacturer and you send it in for a factory repair) to send the dial out to be restored if it was damaged due to water ingress- which happens easily if you don’t have the crown and rear seals replaced at service. People typically didn’t service watches unless something happened (still the case for 99% of watch owners- even among watch enthusiasts), so it was common to wear a watch daily- well past the point of when you “should” have them serviced, and then moisture gets in from overzealous hand washing, freak rain storm, hot sweaty humid day...you get the picture.
Some redials are done very well, some not so much- results vary widely. As collectors, we typically value originality above all- even if there is damage. Some love the look of a time worn watch- showing it’s years of life experience (known affectionately as wabi-sabi). Some of us hunt down as close to perfection as we can and are willing to pay for it.
Nobody but you and freaks like us would know that dial was redone- and most people couldn’t care. The person who bought my redialed Seamaster knew it was redialed (I told him if course), but he didn’t care- he was smitten with the watch.
I would get done what needs to get done to wear the watch daily and enjoy it. If you decide to sell it down the line, you will probably not lose anything considering the bracelet made up for half your investment and you will be able to get something back for the watch- it’s good looking and to anyone but freakish collectors like us- it will be desirable. Just make sure you disclose the redial so you are morally on the right side of the transaction when/if you sell it.