The oil line to the rocker arm shaft IS NOT a 1/8" diameter line! It's 3/16"!
If the oil connector is rethreaded to accept a 1/8" pipe thread, the fitting illustrated in the link with a 1/8" NPT male thread on one end, and a 3/16" tubing compression ferrule and nut on the other is a viable option. It would be better to find the OEM fitting, if they still exist, maybe as new old stock at a parts store that's been around for a long time. The same type of fitting in 1/4" tube size was used for a fuel line on flathead Ford engines back in the late 1940's. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!