I posted my SD here, first, a couple weeks ago. Got zip response. I think it has alot to do with what you're selling, for how much, and a big part is where you're at. I'm kinda up here in the middle of nowhere, in N. Utah, and wasn't selling a hard to find model, even though I still feel it was priced right.
I say, try here first, maybe a week or 2, then slide over to Ebay. Just a thought.

__________________
past MB rides:
'68 220D
'68 220D(another one)
'67 230
'84 SD
Current rides:
'06 Lexus RX330
'93 Ford F-250
'96 Corvette
'99 Polaris 700 RMK sled
2011 Polaris Assault
'86 Yamaha TT350(good 'ol thumper)