I'm not familiar with the MG answers to the GS and was wondering about that possibility.
As for the comment of wanting a pre 91 GS, it's more than fairing or seat foam (I know nothing about that), or the speedometer.
I've been repairing airhead speedometers for ten years now so can tell you there's no real difference between any of the GS speedos or even the earlier ones. They've all got the same basic mechanism. If the needle wavers that much but is a relaxed sort of wobbling around, it's probably due to the damping fluid migrated away. The movements are pretty sensitive, and just like your multimeter, if it gets bumped, the needle moves. It's when the needle has a ragged jerky movement to it, or makes screechy noises, time to disconnect the cable. Bad stuff is imminent!
The tachs are all electronic on the GS - the G/S didn't have one, although a small one was available special order. I rarely hear of a tach going bad - if there are problems, it's usually connections or some issue with the ignition. However, if something does go haywire in the tach, it can kill the ignition - cause it to fail or not operate - one thing to keep in mind.
There were two versions of the GS - 88-90 and 91-95. In 1989 the PD first appeared with the 9 gallon tank and different gauges arrangement - Large speedo on the left, small tach and clock on the right. The basic GS stayed the same with the one large speedo - same front bodywork and gauges as the R80G/S. The PD continued through to 95, and from 91 on, it had a large tach on the right instead of the small tach and clock.
There were small changes as the years progressed from 88 to 95, but the biggest (in my opinion) is the electrical system. It got the wiring and controls from the K bikes - more complex turn signals, though easier to use, handle bar switches that wouldn't interchange with the earlier airheads, only the Ks and new 1100s. A load shed relay (the system that turns everything off when the engine is being started) that can make trouble shooting extremely difficult. It's a really expensive complicated relay costing a hundred bucks or more. It's one of those things that should really be re-done. Get rid of all the complicated wiring generated by the absence of a light switch, and the German affliction of solving issues before they ever surfaced (and never would) creating unimaginable complications.
The pre 91 electrical systems aren't exactly simple, but nothing like the ones that followed.
The pre 91 GSs had plated spokes that can rust after a while, the newer ones are stainless.
I've had both the early and late model GSs - right now have a red 1990 PD and a yellow 93 PD. Love em both. Rode the 93 to the 90S rally in PA a couple years ago (3?) and I think it's a better RT than the RT. Did 3.000 miles in slightly over 3 days and wasn't at all wiped out. The large tank doubles as a fairing and with the tank paniers I was totally shielded except for shoulders up.
I had a 92 PD around 2002 and sold it to a neighbor. He put 100K on it riding to Alaska several times and all over the west. Yes, these bikes have some electrical and electronic bits, but they're easy to diagnose and easy to carry spares. It's not like the newer bikes where an obscure little fault can leave you dead in the water. Yes, diode boards can fail - I've carried a spare but never was needed. Same with the alternator rotor.
I hope someone fills in the Guzzi side of the equation. How do they compare to the GS? Are they expensive? Difficult to find? How durable are they? Weak areas? Driveshaft issues? Etc...
