Some of the hills in the East Bay are very steep indeed. 10% is common and 15% is not uncommon. Worthy of a triple crank. You might drop by a local coop and see if they have a triple road crank and suitable bottom bracket, that would look and work right with the bike. Save the current pieces, of course.
I would replace the tubes and tires (something like a Panaracer Pasela only costs $30/ea and comes in tanwall which would look great). Coming down those hills is no time for a failure. I once bought an old bike and was descending a hill at >25 mph when the old tube split, blowing the old tire's bead off the rim. This was the front tire. A crash was barely avoided.
I will definitely replace the tires. I hadn't thought about a triple on the front. The bottom bracket is Campy, would a triple crank require something different? I will switch out the current 5 gear freewheel for a 6 gear Shimano with a 34t gear first and see if that is enough.
I appreciate everyone's advise.