You are referring to the Sterling by Musicman SUB 5 or the Musicman Sterling SUB 5?
The first one is pretty great bass. Very good finishes and not so great electronics. A bit noisy pre and a very (extremely) hot output Pickup (i screwed mine down to almost bellow the pickguard.
It has a pretty close Stingray Sound and a very great bass for that price. (bought mine for 220 quid or so second-hand)
If its the second one (i know the Ray had a SUB version.... Dunno about the Sterling), well it must be MIA with lesser paint options as the not-SUB one (no high-gloss, the "made in st. louis..." is a sticker instead of painted, etc)