"Vintage" high end gear vs new and upgrade path?

Those maggies are great i still miss mine yrs later . I ran krell on the bottom and cj tube on top with pv12 pre  it sounded killer . Still look for that airy sound . (With 2sunfires) I like it all , but with all due respect the anologue is your weakest link imo planers love a great anologue front end .Just  my opinion but i would look at room treatment,ac and interconnects and the top would be front end .

Speaking of Maggies, the Tympani line of Magneplanars is a special case. The speaker had become too expensive to manufacture to allow Magnepan to continue offering it without raising the speakers retail price above either A: what they wanted to (to keep their image as a value-orientated company), or B: what they thought the market would bear. They reportedly have admitted that the Tympani T-IVa was (actually, is---they are available used, and can still be repaired by Magnepan) superior to any of their current models, even the $14,000 MG 20.7. The cost to manufacture a Tympani model Magneplanar (three 16" X 72" panels hinged together per speaker) now would require Magnepan to price the speaker above what they are willing to, for the above reasons.

Go for it my friend.
I'm on your side.....
Now I'll tell you how to max out your analogue front end to give you better sound than most of the high-end crowd can even dream of.
Don't get the Rega arm but take boxer's advice and get a good vintage arm with removable headshell like the Victor he mentions or the Micro Seiki MA-505.
Then you get the Yamamoto carbon fibre headshell (direct from Yamamoto in Japan).
Then you get a used Shure V15/III from HiFiDo for about $230 (don't bother about the condition of the stylus).
Then you get a Jico SAS direct from Jico in Japan and insert it into the Shure.
Then my friend, you sit back and listen to sounds that you've never heard before......😎

From reading your question and revealing your impressions it pretty much mirrors my experiences and biases for the most part. I believe your analog front end could certainly be improved upon but at what price and are you willing to pay it?

I am of the firm belief that electronics HAVE NOT improved that much over the past 25 years, at least I can’t hear it. Passive components that make up those electronics certainly have in many cases. I currently have two vintage era components and they are have both been upgraded with newer parts, including capacitors, resistors, diodes, wiring etc with dramatic improvements. Of course the key here is starting with components that were good to begin with in which case you certainly have. Digital on the other hand HAS improved and might be the biggest bang for the buck improvement you can make.

Sometimes "better" and "improved" are really synonyms for "preferred". In my particular case I definitely prefer my upgraded 25 year old preamp compared to 5 different newer ones I’ve listened to in my system 3 of which are current. The upgrades made a big improvement but I wouldn’t have sprung the cost if I didn’t really like what I was hearing to begin with. So that should be the first question you might ask in going forward, do you really like what you have but want to improve on it? In which case it is a lot easier than switching out things to "improve" with a less certain outcome.

The points BDP24 makes are valid as well, some products made in the past would be prohibitively expensive to manufacture today although might be preferred to current offerings. In your case I would focus on less expensive tweeking that could certainly improve on what you have without overspending and see what happens. The key thing I have come to realize is that what at first may seem an improvement may later be seen as an unwelcome intrusion! Things aren’t always what they seem as witnessed by the constant "improvements" that audiophiles strive to achieve. Sustained enjoyment of recorded music should be the end goal and is the only thing that matters in the long run.

You'll be forever chasing your tail unless you establish a frame of reference. If it's the recreation of live music, for example, then what venue... a nightclub... first tier center Lincoln Center? Once you establish that then you can easily judge what component helps or hurts -- regardless of the sonic gymnastics or the technology. That's the best strategy I can think of and the one I've always used. I have been using the same speakers and amplification front end for over 20 years.