Hello.
First let me apologize for being so uninformed. I did try to read sheldon brown on the subject but still have a couple of questions, so here goes, and thank you in advance.
I have an older road bike and the fork is pretty rusty on the insides of the blades(?). Not the inside of the tubing mind you. Maybe the best thing to do is soak it in that oa stuff you guys talk about. But I've never been attached to the fork because I'm pretty sure it's not original.
So my main question or questions, if anyone could be so kind as to enlighten me, are:

If I were to get a new fork would it be wiser to find the 1 " threaded which I assume my bike uses(late 80s ish rossin) and if so where is ebay my best bet.

Or

Is it possible to get a newer fork hs and stem and afford myself a little more fit customization?

Thanks again