I found a "used" 20 gauge on gunbroker late winter and yes it comes with a spacer to increase the LOP. Mossy Oak New Breakup, and not a speck of dirt on it, a true safe queen. I paid $300+ FFL transfer fee to a guy local to me, and came with the 22" smooth bore and 24" rifled barrel with fiber optic adjustable sights.
I'm shooting 2.75" shell, with 1 3/8" oz. of TSS #9s using the IC .555 choke tube.
Hope this helps.