[ARC5] ARC-5 with Upper and Lower Sideband switch?

[Tom Bridgers]

There's a BC-455 over on the Bay side (# 5702924629) that claims to have
upper or lower sideband selectable with a switch.  I've seen this done
primarily with crystals on either side of the IF freq., but how would you
accomplish switch selectable upper or lower sideband on an ARC-5 if you
didn't use crystals?  (My assumption is the one on the Bay doesn't use
crystals...)
Thanks in advance for your thoughts,
-tom