OK, since 'specifics' seems to be the hill you want to die on...That's a good answer and certainly covers your point of view. Unfortunately it still doesn't give respect to the OP as possibly knowing what they want. I respect that Mauriat has lots of different models as does TJ. Have I tried them all or remember the models of all the ones I tried? No. Are they vintage horns? NO, and neither is the Ref 54. That doesn't change. This is about specifics. The OP was specific. He didn't say I'm a beginner looking for advice about what horn to buy and maybe I'd like a vintage horn. Please advise me if vintage horns are a bad idea. You have presumed that they have no idea what a vintage horn is and should open up a search including modern horns. You have justified that well, but you're still not giving respect to the OP and what they have stated as their preference.
In the oddest of ways I agree with you, as I own (and have owned) a number of horns, vintage and modern. The tenors I play regularly are modern with Vintage type sound (R&C and Borgani). There is no disrespect intended towards your knowledge or opinion, we just need to give help that's asked for. In that respect several of us have already flagged that vintage horns are worn and may require an expensive rebuild.
The OP said " I am thinking along the lines of a vintage Tenor." - so that's specifics out of the window.
You claim the OP knows what he wants. "possibly a degree of character and vintage nostalgia". Again, not specific.
And finally "What recommendations/ advice could you offer please?
Now, I don't mind going out a limb here and saying (with the utmost respect) that the OP hasn't got much of a clue about vintage horns - or indeed any other kind of horns - and certainly has zero experience other than that afforded to them by the Yani 902. The latter was stated, the former is evident from the question - which was about as vague a request as I've ever seen (no biggie, we all have to start somewhere).
So in my opinion my recommendation is to try some of these 'halfway house' horns to see whether that 'possibly' is a path they really want to go down, and if so what direction it might take.
That's my professional position, and I'll stand by it. If you feel offended by someone tipping over your hobby horse, that's your problem and you'll have to find a way to deal with it on your own time.
If the OP wants specific details about the horns I mentioned, I'm sure they'll pipe up - and I'll be more than happy to help - but I'm through playing semantics with people who, very frankly, ought to know better.