Recently bought a 1973 R75/5 toaster in great shape. Also purchased some original tools and the owners manual for the /5 series. On page 14 the grade of fuel is specified as 99 octane (ROZ) for the R60 and R75. Is this a typo or was there some other octane rating back in the day. I had a R60/5 back in 1972 and don't remember having run any thing other than regular gas in it for 60K miles.