Is the off-white color of my old turbo saddle original, or was it whiter when new? What material is it (it feels felty) and how should I clean it if there is a chance I can brighten it up?

I believe it came that way. I think the covering is Alcantara.
I have a white, smooth leather version of the Turbo.

If you look on the underside there should be a lip of material that is folded over the bottom. Typically, it does not get the wear, tear and exposure that the top side does and should be be representative of the original color.

It's the same color - thanks. The alcantara website said to clean w/ damp cloth, that's all.

BTW I know saddle fit is subjective, but I have a 22 year old turbo saddle and LOVE it! I hope to get another 22 years out if it, if possible. It's scuffed in the back from some crashes (from my racing days) but otherwise has held up beautifully.

I know where you are coming from. Even though saddle technology has improved greatly, I am still most comfortable with the 1970s Unicanitors. I pick them up whenever I find one, so I can have them on as many of my bicycles as possible.

Me want one

I have one on my Proteus....I love it and the way it looks!