I don't remember that dynamic mic sounding this bad.
Maybe you used to think it sounded good, I have recently gone back through some old recordings that i made and the quality was terrible, but at the time i thought the mic sounded great.
could be your ear is getting better.
I find that you have to pay alot more for a dynamic to get one with good sound quality.
Condensers are dirt cheap and sound great, but also have a very large pickup area, i can hear this with my MX990 and AKG condensers.
Tom JJ has had great luck with the radio shack corndenser mic, I would try stuffing one of those into the old shell and see how it sounds.