Help me choose, used but excellent cond Maggies - Maggie MG12's or SMGb's

I would recommend just getting a new pair of the LRS. Older Maggies can suffer from dis-bonding of the wire on the panel. Magnepan is not doing repairs or supplying parts at this time. The LRS is a good product or you could find a used 1.7 if you have the room. SMGs and MG12s are starting to show their age. 

OK fair enough. I did see some great accounts of the LRS when trying to find out more about the other pair - obviously in the States you have the privilege of paying such a small amount of money for these.
The MG12s are 2002 - so is that old enough to "show their age"?
I suppose with the new LRS there should be no need to consider a second hand Maggie anymore if they are good as the reviews state.
Any other opinions?

As an aside - how to do much older Maggies like the MG-1 full ribbon speakers sound in comparison to these newer models?

A pair in good shape of course!

"...The MG12s are 2002 - so is that old enough to "show their age"?..."

Well that’s 20 years now. A lot depends on the environment they are in. High humidity is the worse environment for the old glue system. Newer Maggies have improved that issue.

"...As an aside - how to do much older Maggies like the MG-1 full ribbon speakers sound in comparison to these newer models?..."

OK, let me get my terminology defined. Old Magnepan loudspeakers are Planer-magnetic with wires bonded to a Mylar substrate. Newer Maggies have a flat circuit pattern bonded to a Mylar substrate. The large models have a true ribbon tweeter, an element without a substrate backing. Except for the tweeters, new Magnepans are quasi-ribbons and of the planer-magnetic design. Some single pull and some double pull.
A fully restored older Magnepans still sound good but they did get incrementally better over time. The main issue at this time is getting service if you have a problem. Best to start off with a fresh pair.