TIFU by selling one of the droids I need for RB20

A couple days ago, I made RB19 and had 2 out of 3 of the droids I needed. I just needed the 2Trillion credits. No big deal, right?
Over the past couple days, I got the 3rd droid and put the Cone on its head. I do this with all 3 droids needed to RB.
The other morning, I look in my lounge and see I have soooOOooo many monowalkers and I need room. So I sold them all, knowing I had a monowalker out working somewhere else in my base with a cone on its head.
Except it was a cyclowhatever. For my RB20 I needed a monowalker and a cyclo-thingy and I sold all of my monowalkers.
I still need about 250B credits, so I've got time to re-find that monowalker, but man...... do I feel stupid.