Replacement parts for the old radiators in my home

I have been looking for replacement parts for the old radiators in my home. I haven't had any luck with finding a dealer in New York. The only place i did find was a place in Mass., but i fear the shipping charges. I am looking for replacement valves (standard) and replacement knobs. The ones I have are leaking where the knob and valve come together. I have tried plumbers tape, but this has been only a short term fix, as they are leaking again! The knob is stripped where it enters the bonnet nut on the valve. Any help and/or advice would be greatly appreciated. I fear that the continued leaking will ruin the surrounding flooring. Thank you for your time.

Steam or Hot Water Radiators? I did a quick search on Yahoo search for "Steam Radiator Replacement parts", and came up with quite a few hits.

HI,
Seems to me they need to be repacked. I don't remember/know much about it other than that we had a leak in one of ours (hot water heat) and the furnace guy told us something about repacking. as for knobs, try ****.
Good luck,
AMy

I just bought a radiator valve at Home Depot today for baseboard cast iron a friend was putting in for me.

Now this is in Chicago so I don't know where you live.