Does your rear hub take a freewheel or cassette? The majority of 126 mm spaced hubs took freewheels, which means you can't put a cassette of any size on it. Check this first. If it's a freewheel, your only options for a cassette with indexed shifting would be to respace the rear triangle and buy a new rear hub/wheel.
Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72