I am the original owner of a 1970 Raleigh Super Course. The SC has gone through a few changes over the years, including a Suntour Derailer V GT Luxe. The crankset is original(Nevar) as well as the brakes. Not sure if the rims have been replaced. My son used the bike for several years, but now I have it back.

I primarily use the bike for commuting and sometimes longer rides up to 40 miles. Is it possible and/or feasible to extend the gear range for easier hill riding. I would also like to replace the crankset with a cotterless one. Any suggestions on how to proceed would be greatly appreciated.