I recently purchased a older one speed cruiser at a garage sale and am having some trouble locating parts for it. I don't want to "restore" it, only to ride it around safely.

For example I would like to put a longer seatpost on it (13/16" I think), and a new crankset (one of the old pedals is crossthreaded), but I haven't found a good online site for such parts.

The bike closely resembles a Schwinn "Heavy Duty" though it has no badges and I can't even determine the manufacturer.

Can anyone suggest some online resources for these sorts of parts? Catalogs?

Thanks.