Is is most likely bronze and does a decent job.

There are newer seals available, but it is unlikely to be worth tearing out otherwise functional seals.

Try 'Resource Conservation Technology' in Baltimore, MD for all sorts of door and window seals.

I have replaced that kind of copper(have seen the brass as well) weather stripping with new stuff of the same type---to satisfy the home owners desire to remain period compliant.

The latest design that would be the best replacement would entail the removal of the doorstop section of the jamb and cutting a 1/2" deep dado in the stop(or replacement stop) to allow the rubber weather stripping to be installed in that slot.

That also would mean the door stop would have to be relocated and the jamb refinished/repainted.

The new rubber collapsable weather stripping is much more energy efficient as well as maintenance free(other than an occasional cleaning if needed). The major problem with the copper type is getting clothing snagged and tearing the metal. And it can be noisy in high winds.

The other nail on types of weather stripping are less functional than the copper, IMHO.

Why does it need replacing? Perhaps you can just bend it back out to make greater contact with the door.

It seems to be in good shape. I'm planning to replace the door and just assumed that 1964 weather stripping should be replaced. I thought that there were probably superior products available now, but I don't want to get into a complex replacement project if what I have now is adequate.

I made the mistatke of taking off the copper stripping and now cannot find any to replace it. Anybody know where I can purchase it?

Do a search for "spring bronze door weatherstripping" and hundreds of sites will come up.

Ace hardware even lists it.

I would leave it if it is good shape.

As Brickeyee said, it does a good job and can last forever unlike the newer stuff.

I agree with this comment. I am only finding bronze spring weatherstripping. Copper is probably only available from specialized salvage yards. I am dealing with trying to remove paint some clown painters covered mine in. My house is 1938 and I'm trying to conserve it. So I don't want to damage them or replace them.