In the Netherlands they are called "Ed Pols platen", when you Google that you'll find info and pics
Here's some info on Halflive's page ( in Dutch )
1300cc 217Nm/207Hp NOS-injected VMax (1985), 500 cc 1950 BSA chopper (1983) in pieces, 750 cc CB750 chopper (1990), 300 cc MZ transporthack (1989) winterhack, 900 cc BMW R 90/6 hack (1976) summerhack, 1100 cc BMW R1100GS (1997) daily driver.
Age is an issue of mind over matter. If you don't mind, it doesn't matter ( Mark Twain )