The plug for the H-4s is identical to the three prong plug for old sealed beams (at least it looked the same to me). The plug is part of the complete assembly. The only adaptation you'll have to do is pick up a pair of 6 pin connectors and covers, about $7.00 at the dealer, and rewire the connector ends of the harness. Very simple.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.