Crabby, I have never noticed any engine compartment smells in the cab of my 59 not to say that it couldn't happen. There are rubber grommets that should be installed where your wiring etc passes thru the firewall or floor. Perhaps yours are old, brittle/broken and need replacing. An application of RTV may also help seal out the smells. The insulated firewall cover I went with was marked where holes would need to be punched. A hole saw works best for the ABS plastic or fiberglass but not the insulation material. For this you will need a very sharp knife or razor blade.
Bruce


Bruce
Old Toy: Ol' Betsy stock 59 Apache SB Stepside (Gone but not Forgotten)
New Toy: 1962 Impala SS Coupe
The Driver: 1990 Toyota truck