I just completed a total ground up rebuild of an FM-3 using Chauncey Epperson's (www.FM3zone.com) motherboard, upgraded power supply and PRC modules as well as all new components from Mouser. This project turned out great and Chauncey's gear and help were first class. I can highly recommend his products as top quality and his backup advice is very knowledgeable.
The tuner operates with virtually no noise and pulls in stations well. I had bought 6 tuners for parts on eBay and also restored two others but the Epperson modded version is obviously superior in every respect. One of the others also has an Epperson upgrade kit in it without the motherboard which did make a big difference but does not come close to the dead silent motherboard model.
Anyone considering upgrading or re-doing their FM3 tuner would be well advised to check out his products.
I will post some pics of this and the other tuners with partial upgrades.