George S posted:If you are cutting O27, you might get by with a hacksaw. If you’re cutting O, forget it and buy / borrow a power tool. It’s next to impossible to cut by hand.
George
My descriptions above were all for Lionel O Tubular, so it's not impossible. Start slow with a few strokes in a single direction, preferably pulling the saw towards you. Probably repeat as you make your way through each of the three rails. This is a benefit of cutting with the track extended over the end of a table - you can easily do one rail at a time.
I've never been an O27 guy, so I've not cut that with a razor saw. Presumably it's a little easier, assuming the force on the track doesn't deform it since it's lighter.
Here's a link to the saw I think I have. Many hobby stores carry these. (Yes, I'm aware the description doesn't say it will cut our track, but it does go as far as suggesting copper and brass - as I said earlier, it may lessen it's life, but for under $10, it will work for a fair number of cuts)
Or you could try one of the many power tool focused answers that you specifically said you were not interested in in your first post. 
-Dave
