I'm sorry this happened!
The rigs are not still on the MAC? No Backup files from Rig Manager? No old USB backups?
Oh no, 'Pudgie! Geez man. How awful!
Do you not have backups or old partitions that might contain the (from the Mac) User / Lib / Application Support / Kemper Amps / RigManager folder? This one contains a database of everything you had in RM, which you could obviously restore, by copying them into the Local Library folder therein on another Mac, after which you could drag and drop your rigs to a FAT-formatted USB stick and transfer them to RM on the PC.
Are you sure you haven't got any backup files made with the Backup / Restore menu function in RM? That's just a single file and would be the most-convenient option, obviously, and also the least-likely you'd not have already explored.
I'm so sorry for you man. Major bummer. The silver lining is that you'll never allow this to happen again.
Hang in there, bud.
Thanks for the suggestions, guys. Let me check those locations on the old Mac (thankfully I didn't get rid of that) and see if I can somehow restore my collection.
What a night. 
Oh man, if you've got that Local Library folder in your User / App Support / Kemper Amps folder, you'll be good to go, brother!
The K-Team™ recommends we never mess with that folder 'cause it could cause performance / stability issues in RM down the track, especially after updates, but in this case, you've got nothing to lose. Fire up RM on the Mac, create the equivalent folders in the Finder to what you've got in the app and drag all the Rigs (select all - command-A), folder-by-folder to the ones in the Finder.
Once you're done, do the USB-stick boogie I described and you'll be solid, mate!
Sorry to hear. 
I always put copies of my paid profiles in the cloud.
Nicky's advice could be worth like gold.
With your old Mac RM you can send all Performances and Rigs to the KPA. (store at first all your tweaked Rigs/Performances from KPA)
With PC RM you can upload again. Its a drop and drag game.
I hope for you to succeed
Hooray!
If you have any issues with USB drives:
There many other ways to transfer them. Since kipr files are not platform dependent, You could email them to yourself as attachments, put them in a private Dropbox folder, etc.
Most sellers should have a store so you can redownload the contents of your purchase 
Most sellers should have a store so you can redownload the contents of your purchase
And those that do not have already graciously responded to my emails and provided either new links or zip files. I am truly grateful for the showing of support I received from the community.
It's been a weird couple of days here in the US. Glad I could find some comfort here. Sniff, sniff.
We only share love here .
... and Profiles! 
Fantastic news, 'Pudgie!
