Public Service announcement: It appears that one of Paul's 500A DC controller kits is posted on ebay
https://www.ebay.com/itm/313326781399?ul_noapp=true
At least, that's what it looks like to me .. from the pictures.
The seller does not appear to ship to Canada, so I'm out
I forgot about sending files to @Staircase ... I'll try to get that done this week