if you want true red, go with the SF one...they use kodak photo quality glass. I bought a Streamlight "red" filter, and it's sickly orange...I'd send ya that for free, if it would fit, since I was going to throw it away anyways...
If ya don't want to pay $35 for it, try the market place. You can post in the WTB section. I just sold my like new one for $27... you should be able to grab a used FM15 for around $25...welcome to cpf, btw.