That Retrospec bike is the first time I've seen one mentioned since I bought my Retrospec folder earlier this year. Previously I'd never heard of the brand.
Same as rick, I used Campy grease then Phil for decades.
I've been using Quicksilver marine grease 2-4-C with PTFE in a tube purchased at my local chain auto parts store. It has a terrible smell but is working well.
there are so many inexpensive e-bikes available, maybe not as cool as your OCC, but I'd go that route and leave the OCC as is. If you decided to tackle this project, I look forward to seeing it progress.