Oppinions on getting an add-on FM-MPX decoder

[Electronic M]

Lately in my quest to make my stereo system more tube based I've been looking for a tuner. I ended up buying a Fisher AM-FM simulcast stereo tuner that looks like a simple project. I bought it because I've read that the AM sections of simulcast tuners tend to have better audio quality than most others.

I plan to add an outboard FM-MPX decoder to the mono FM tuner in the Fisher...I want to go with a tube based unit obviously, I want to spend as little as I can, and I want to get decent performance out of it.

That said there is an RCA RK295B FM-MPX adapter on the bay I'm considering buying. http://www.ebay.com/itm/Vintage-RCA-...item418a45b386
What I'd like to know is: does anyone here have any opinion on the performance of it relative to other decoders out there, and should I wait for something better to show up?

If I wanted to be really cheap I think I might be able to salvage a hybrid MPX decoder out of a gutted Silvertone tuner chassis I have (although it may be a single board tuner design which could complicate things).