Wanting to avoid pitfalls of modern tyres on 90's Trek

[hamster]

Schwalbe Billy Bonkers and Conti Race King work well for me in very similar conditions.

 

[Retrorockit]

Modern tires will upgrade that bike immensely. I was going to suggest Rene HERSE Extralight tires. But the Scwhalbe Billy Bonkers is hitting the weight target (490g knobby) for much less money. There is also a 26x2.00 version with reflective side walls. This may be required in some places.
But you must get the Perfomance folding version. The ones with wire beads, and Kguard flat protection layers are heavy. I use sealant in the tubes instead. I've had a few flats with the layered tires. Much better luck with the sealant in the tubes..
https://www.schwalbe.com/en/Billy-Bonkers-11654538

 

[el_Pedr0]

Thanks for all your suggestions. Shortlist came down to Nobby Nics and Panaracer Fire. I've taken the risk on clearance and gone for Nobby Nics because they have had more iterative innovations giving me the feeling that they might have the upper hand in performance, technology, and execution. If I struggle on clearance, I'll fall back to the Panaracer Fires.

I couldn't quite get my head around billy bonkers' little teeth and how they wouldn't just turn into slicks in mud.
Panaracer Smoke/Dart are widely liked off road (again from mid 2000's comments IIRC), but some suggesting they were draggy on tarmac.
IRC Mythos - I didn't do enough info research to get insprired (e.g. don't know about compound performance, or how widely well recieved they are)
Marathons, Land cruisers etc - While a knobbly tyre can be a drag on tarmac/dry trail, you can keep going. However, wheels spinning or slipping in mud can bring everything to a halt or make things sketchy. For me, sub-optimal performance on long distances of hard surface doesn't drag me down, but getting stuck or falling in the mud can make me a bit miserable within an instant. So I've realised I've got a bias (rigthly or wrongly) to veer towards the knobbly end of the spectrum.
Magic Mary - I got the impression that this might be overkill or not targetted at my riding. Perhaps intended for a more aggressive, specific type of riding (gravity).

 

[Retrorockit]

FWIW Panaracer makes the Rene HERSE gravel racing tires to their specs. The RH handmade Extralight knobby is probably the fastest and lightest all-road tire out there. But the price is a legitimate issue for many people. RH claims it rolls just as fast as their slicks, which I can tell you is pretty damn fast.
https://www.renehersecycles.com/shop/components/tires/26-inch/26-x-2-3-humptulips-ridge-tc-tire/

 

[el_Pedr0]

Went out on the bike yesterday for some very light trail riding and was delighted with the bike. The Nobby Nics feel so much grippier than I remember the original mavrics. And they feel like they roll better on tarmac too. Another huge difference (possibly even more profound) was the pedals. I previously had the original pedals with traditional metal base and a toe cage. I put on some DMR V11 Pedals pedals and the difference is like night and day. It feels like your shoe is stuck onto that thing and it's such a wide base to push on - just gives loads of confidence. I also liked the DMR deathgrips that I put on - much softer than the original grips, but I got on very well with them.

 

[el_Pedr0]

... very, very dry at the moment though - so still don't know whether clearance will be a problem in muddy conditions. (new tyres are 2.25 inches, original ones were 2inches, frame is probably a fair bit narrower than modern bikes)