Transferring Saves to a New PC

I just did something similar. I had several older Tray files on my desktop. Not wishing to lose my builds, I decided to refresh my game folder. First, I pulled it to my desktop to have that tray, and my current saves as well. Then, after the new folder regenerated, I opened up new games wherein I downloaded my lots from the most current Tray I'd placed into the new game folder. I got all the saves I wanted. Once that tray had been secured, I replaced it with the next one and continued with new saves until I had that tray secured. The entire plan was to be able to place all of the saves I wished to keep in a single tray, allowing me to clean-up my desktop. Once you have your saves in place, you should be able to upload your builds to the gallery, (My Library) and from there you can download them again placing them where you wish them to be.

If you wish to have a nice 'tidy' Tray again, place a brand new, empty Tray folder into your game and download from your gallery. The long and the short of it is, you should be fine.