Would getting a pair of Maggie 1.4s be an upgrade?

while there are many members here that know and own Maggies I would suggest that you venture over to the Planar board a Audio Asylum where most Magnepan fans hang out.

wire comes off the mylar (it runs the length of the speaker) and needs to be reattached using glue. I did it a couple of times to an old pair, it is quite easy but not an ideal situation. Sometimes a bit of wire is loose and you need to glue it again etc.

You get the glue from Magnepan (at least I did 25 years ago)

I would not bother with it again myself

Martin, simply put, I think the 1.4QRs would be a music upgrade, but a HT downgrade and that overall you probably wouldn't be too happy with them since they require lots of power (your amp only appears to venture into 4 ohm territory for bursts of power, which is where the 1.4QRs like to hang), they are very room and position dependent, and they have a much narrower sweet spot.

"Regluing" is probably the seller telling you that the drivers in his 1.4QRs had delaminated (the drivers consist of very thin strips of wire glued onto sheets of mylar and under certain conditions and/or over time the glue doesn't hold), a common issue with older Magnepan speakers, that may have been fixed completely or partially, well or poorly. The only way to tell is to pull off the cloth covering called a 'sock' (not an easy task) or shine a light of some sort through the sock to inspect the drivers, and to listen to them - if you hear aberrant sounds and/or see wires coming up off the mylar, the delamination problem probably remains.

Given the aforesaid brief description of caveats of ownership, these speakers could be a cheap easy way to enter into the wonderful world of planar magnetic speakers - Magnepan is a revered company and the Magnepan Users Group on the Audio Asylum provide a wealth of information on Magnepan speakers and the folks there are very helpful. http://www.audioasylum.com/forums/MUG/bbs.html