For my wife-12 speed. Its pink-but I actually kinda like the color-not obnoxious at all. From original owner with original receipt. Bought 11/86. Says it has a "triple butted mangalite" frame. Isn't particuliarly light, but way lighter than the Murray she trashed. Note that I am a forum newbie, but have perused around the site a bit. Anyway, the frame and paint on this are in excellent condition. But, owner said she had never had the bike "tuned up" and felt something wierd when cranking, so she got a new bike. I did not feel anything that out of the ordinary and figure with some work and maybe replacing a part that is shot, it will probably work fine. I have not done much work on bikes, but lots on cars, etc., am mechanically inclined enough to figure most stuff out, and like playing with stuff. I'll handle the tuneup end (looks like I also get to buy some new goodies for tools/pullers too), however if something is bad due to never having any maintenance, would like some opinions. The bike has nameless, obviously low end, shimano stuff-whole group except araya alloy rims and sansin(?) hubs and an aftermarket tall stem that is part metal and part plastic.

1. If freewheel is bad, will any 6-speed freewheel work-Shimano, Suntour, etc. as long as the teeth combination is similar and has correct threading? What would anyone recommend-without going overboard? They look to be fairly cheap and easy to come by on ebay.
2. If rear deraileur(sp?) is bad, same question. Recommendations-whats decent? Will the bike "know" or not work or shift correctly if I put a Suntour deraileur on and leave the other stuff the same?
3. If bottom bracket is bad, go sealed? Is there a standard size? Looks like these are only $20 or so.
4. 20 year old chain on bike. Are there different sizes and what would it take?
5. Hubs-are these Sansin ones garbage? I am hoping these are OK as I do not want to buy wheels. Will pull em apart and check bearings. The rear does not have quick release.

Don't mind spending a few bucks on a couple tools stuff as I can also play with my 78 Supercourse, but I am not looking to upgrade everything or even anything-only if something is shot. Realize that this bike was probably at the bottom of the food chain and not looking for real high end stuff. Bike was cheap, so even if I went overboard and spent $150 (that leaves me with over $100 left to spend-tools don't count), including the cost of the bike, it is probably a better machine than I can get for that $$ today. What are good solid middle of the road components? BTW, we are by no means bike enthusiasts, and at, best leisure riders. I guess I might be making an excuse to get out into the garage and tinker with something to get it in dependable riding condition and cleaned up. Thoughts? Thank you.