You could get some sealing wax, melt it, and pour it down the inside of the tubes of the frame. This will seal the inside of the tubes against more rust damage. Not sure if you need a special type of wax, but you can get microcrystalline stuff fairly cheap from any art materials shop.
You could get some sealing wax, melt it, and pour it down the inside of the tubes of the frame. This will seal the inside of the tubes against more rust damage. Not sure if you need a special type of wax, but you can get microcrystalline stuff fairly cheap from any art materials shop.