There are steel string classical guitars... or classical body guitars that are strung with metal strings. One way you can generally tell if it's a classical guitar is that the fretboard on a truely classical acoustic guitar is generally wider than that of a conventional standard acoustic. If the neck is wide it's probably a classical... and vice-versa. It doesn't really matter either way... A guitar is a guitar is a guitar. the tone is different and you'll find that you won't be able to get the sound of some songs that you may want to learn if it is in fact a classical styled guitar. I wouldn't suggest putting nylon strings on it if it is set-up for steel strings. I suggest simply changing the strings. Strings are that old are probably rusty and may have jagged edges taht are adding to the pain. If you get a new set of strings I'm sure you'll find them much more comfortable.