Hey Pete, in regards to "light" oil, one of the best "light" oils that I have used over the years has been "Starrett" Instrument Oil. It is extremely stable and does not deteriorate over time. In studies we did back in the 60's at Monsanto Research Corp, 3 in 1 oil was the worst of all of the so called light oils. Sewing machine oils were next in line. Mobil Oil makes a great series of oil called DTE. In comes in various grades, but not light enough for our models. If you can not get the Starrett instrument oil and wish some, let me know and I will buy some and ship it to you.
Another trick to try, take a No.2 pencil and rub the side of the lead sticking out on the shaft. This will deposit "graphite" on the shaft and make it slide easier.
My nickles worth. Keep on having fun !!!