err.............err..........I'm verry tempted.
mshilarious, how would one go about getting a ribbon to replace the old one.
First I think you'd need to establish whether the ribbon needs replacement rather than retensioning. Freudian, I wouldn't further tension the ribbon unless you can test it for resonance, otherwise you could overtension it--which may be reversible, but the ribbon is fragile and the more you mess with it, the more likely it will be torn.
The 315 has three layers of screening; the first is the metal grille, which is backed by silk, then the screens right in front of the ribbon. I removed all the internal screening on mine, in an effort to preserve some HF response, and I think it helped. But you would need to evaluate the condition of the screening if you intend to retain it.
Also keep in mind that this is a somewhat collectible vintage microphone, so mods can alter its value. That wouldn't include a competent reribbon, but clearly removing screening would fall into that category. When I got mine, it had plenty of issues to prevent it from being valuable, so I don't mind hacking away at it.
If you go for a pro reribbon, I think it generally runs around $125, but I don't know who is reribboning old Shures these days. Ask around, somebody will know.
If you want to try it yourself, first you'd need proper foil. I use silver leaf from an art supply store, that's not really proper material as it is very thin (0.6 micron), but it's cheap and readily available. It is very difficult to work with, but I've gotten pretty good at it.
Proper material is more like 2 micron, and it is available from some industrial supply houses. It is shockingly expensive for even a small sheet, and you need such a tiny amount (the 315 has a really small ribbon) that it is not cost-effective.
I have thought about offering a reribbon service for Chinese mics, but I haven't seen that there is demand yet. I ain't gonna do vintage ribbons as that's too much pressure
But if it doesn't go here pretty soon it is heading for ebay and you will all have a crack at it there. Could be good or bad for ya