I gave up on Glasgow for 'real' R/C modelling years ago, and just use Marionville Models at the Maybury roundabout, Edinburgh.
There is nice wee shop in Uddingston now, been there for a few years, at the Glasgow end of the Main street.
U-Control, once in Byres Road, was probably the best. Dunn's was good, but city centre made it a pain if you didn't happen to work there. Paisley once had a good shop, but I never used it.
Cheap imports again to blame for somethiing of ademise in the hobby, as you can buy R/C toys that keep the masses happy for less than the cost of a few servos for a proper R/C model.
Have a look at the Retailers section in
these links.
Check the Turbotek (no zut) link for model jets. If you haven't seen these fly, DO, the flight realism without the glow engine buzz has to be seen to be appreciated.