Too bad ya ain't in driving distance.
Yeah, the only difference between the 500 and the 88 is that the 500 has a thumb safety on the top of the receiver right in front of the stock and the 88 has a crossbolt safety (the more common button that goes side to side in front of the trigger). Past that its the same... barrels, stocks, mag extensions & other accessories, and most if not all of the internal receiver parts are all interchangeable.
Didn't include that in my original post cause its all in the link to the ad on the gun forum I'm on, but hell with it may as well post it here too.
And guys, I'm sure I don't have to say this but:
A) You need to be legally able to own a firearm in the state of CO, and
B) If you're a sketchy, shady kinda guy and I get a weird feeling about you, I won't sell you a rock much less a firearm.