Couple of points
1) Put the seat up, definitely. Seat down looks daft and reminds me of when I was a kid trying to ride DH and freeride on my XC bike, which would DEFINITELY put me off a 2nd hand bike.
2) This might get me flamed a bit, but I wouldn’t mention what YOU paid. It should be about what the bike is worth. New 905s retail at £1600ish and yours has arguably similar or better spec. Saying you paid £1149 sort of suggests the bike was only worth that new which isn’t necessarily the case.
3) Some bugger (i.e. me) hasn’t long since saturated the classifieds with for sale ads for a 905, and I didn’t get many bites either. Had more success on Gumtree.
4) Link it to the bikeradar review. Depending on the buyer this may or may not be a credible source, but the review highlighted some of the best charateritics of the bike and might make it more appealing to the buyers.