Where are you? If you're in the US, I can shoot you some for free. If you're outside the US, just pay for postage, and they are yours. Do you need just the springs, or springs and hammers?
Edit: I didn't read your whole first post, sorry. But PM me your address, I will get a postage quote, and I can send you some springs. Unfortunately, it's usually a few bucks to send to the UK what is normally $0.25 in postage costs to send domestically. And I did exactly what you thought to do, but with an old terminal board. Maybe look into that? They typically go for much less than a "usable" model m.