Originally Posted by
skilsaw
Many bikes that age had steel rims that were chromed. They were a death trap when it rained because the brakes didn't work on the wet rims. Better bikes had alloy rims which worked better in the rain. Maybe you can pick up some 27 inch alloy wheels. I would stick with 27 inch because the brake shoes will line up with the rims.
This bike has decent Araya alloy rims so that isn't a problem. The OEM brakes might have enough adjustment (4 mm lower) to align with 700c rims but that will have to be determined. If they are changed to modern dp brakes, he will need long reach ones and he'll still have to see if the adjustment range is adequate.
To the OP: I had an '85 Bridgestone 400 (one level up from your bike) as my first "good" bike so I know why you like yours. I'd do the few changes Bezalel suggested except you will need clamp on downtube shifters as there are no braze-on downtube bosses. Perhaps using barend shifters, which will let you continue to use the current clamp-on double cable housing stop, would be more practical. New bar tape and aero brake levers are well worth the minor cost.
I would not try to make this bike "as light as possible". Therein lies a money pit of great depth and, while the bike is very nice, it's not worth a huge investment. Enjoy it for what it is and make only minor improvements and upgrades. If you want something super light, start with something else.