That can happen, you wait and wait and wait, and during that time you decide to seek a different path, and the next thing you know - it arrives !!
When I first glanced at your post, I was like - wait - it just came, and it's for sale already ?? but after reading your post, I totally understand why you are doing this.
A while back, I was really into the idea of a 12 string Railboard, to the point where I was all set to make a deposit and then do extra payments during the build so the pain would be much less once the day would come, but - in retrospect it's a good thing I did not go that path, and instead chose to modify my RB - 8 so it could do exactly what I need it to do, which it does very very well.
Good luck selling your SB-8, those are very exciting instruments when set up like 2 bass guitars, Classic 5ths C G D A and standard 4ths E A D G, with the heavy strings running down the center, so I guess it would be looking at the instrument laying on the floor with the headstock in front of you:
A D G C E A D G
Grace turned me on to that tuning years ago when I had no interest in a Stickbass whatsoever, yet today it's by far the most exciting instrument I own, along with my RB-8 set up in Crafty tuning [my idea] with my own bridge mods after the fact to make her really really shine
So if for some reason there's no nibbles on your new instrument, and you are able to keep the instrument from a financial standpoint, if the tuning it came in bores you, that 5ths 4ths bass set up i just described might really make you reconsider selling your new instrument - trust me on that
Cheers