'96 Seat and engine cover gas strut

Anyone have any suggestions on where to get replacement gas struts for the observer seat and the engine cover an clamshell?

All my struts say SL-36 but have various inconsistant numbers on them. They obviously have different ratings depending on the load. But the other numbers don't make sense.

I have:the following:
Observer seat: SL-36 043/96
Lower engine cover: 264/95
Clamshell: SL-36 6U 60, 002/96

I assume I could get these at an autoparts store if I could figure out which # rating they are.

Any help is appreciated.

Gordon
California
'96 SN, GT40, 1,600 hours and going strong