Just replaced the factory black synthetic stock set on my 590A1 with aftermarket ones. This set is in VG/excellent shape -- there is a 1/4" flat mark halfway up the left side of the pistol grip as shown in pic, and a very slight 1/2" scratch above that (not big enough to show in the pic). Some marks on the bottom of the recoil pad, too. Otherwise it's perfect, as far as I can tell (the jpeg makes it look dirty, but it's clean -- dunno why it came out that way).
This should fit all 500 and 590 Mossberg variants that have the standard 8" foreend. It attaches with the regular buttstock bolt (not included). Comes with factory recoil pad and parked sling stud, but no sling swivel. SOLD PENDING FUNDS
I prefer USPS Money Orders, but if you don't mind patronizing antigun companies I can accept paypal via a relative's account. IM, email via ar15.com or directly to email@example.com