here it is my simson s50 b2 completely transformed and basically a s51 now.. I'll answer any question! Been building it for quite some time now and im not done yet. :
Simson S50 B1 Moped in weiss S50 S51 in Sachsen - Chemnitz | Mofas und Mopeds gebraucht | eBay Kleinanzeigen
Simson S51 3-Gang Moped Mofa Roller S50 Lampe in Sachsen-Anhalt - Osterweddingen | Mofas und Mopeds gebraucht | eBay Kleinanzeigen