"H 19" is a sheet metal date stamp. The "H" is the year, starting with "A"=1960, so "H"=1967. The 19 is the week# in the year.
For example, "H 19" is the 19th week of 1967, which starts on Sunday, May 14 -- which makes sense given your car's assembly date.
Not sure about the 'R' but I agree with the other folks who say it means right-hand-side.
P.S.: Count the gears...
