Some have converted to H4 with significant modifications, but I just Found on CMSNL.com the original headlight.. This might be an option for those here in the states that want to convert to a replaceable bulb. sure they are pricey, but they made them until 1992 for the Euro market and the assemblies are plentiful.
part number is 33120-GC7-611
and they shipped it to me from the netherlands in the original Honda box in 4 days. simply amazing!


you have to get a replaceable bulb plug from Napa, (or a junkyard) but some simple wiring is a lot easier then milling out the assembly and gluing in the socket like others have done.