I think that RSSteve lives in Jupiter which is probably less than 1 hour north of Broward. He might know about a place in Broward county. He's got a "bunch" of Fisher gear. In fact I'd like to know if there is a place there too. I've got a son that lives in Ft Lauderdale and it would give me two reasons to visit the county area. (I don't get there much.)
I refurb'ed my KX-100 myself (Almost identical to the X100B). It wasn't hard, but I have some electrical background and a lot of patience. Got any idea on what kind of work you need done? Typically if it is just old, you can get by with replacing the electrolytic caps and check the tubes and visually look for obvious problems. There are some recommended mods that will help too such as bias improvements, output tube measurement resistors, output tube grid protection resistors, inrush current limiters and more. I don't know how different is the X100 vs. the X100B, but you can get lots of help here in the Fisher area of AK. The people here are really really helpful and friendly.
My KX-100 was in really bad shape. It was missing tubes, switches, and had a blown output transformer (that I was able to save). The chassis and transformers were covered in rust. I basically had to go completely through it and it took lots of evenings to get the rust off without damaging the stenciling too badly. I've been working on it for a bit over a year (with fits and starts). I'm on the last couple of things to tweak and then I'll be done with mine. It's a nice little unit. You might want to post in the Fisher section to see if anyone else can give you suggestions about support in South Florida/Broward. Maybe just finding a place that has a tube tester will get you more leads too.
My tuner is a Fisher KM-60. It's a basket case right now and needs a full refurb too just like my KX-100. The KM-60 was sold as a kit and it might be the kit built version of your FM-50 (or pretty close). That is next in my queue. I hear they are sweet when working correctly.
I'm in the middle of refurbishing some Fisher Kit speakers too. They are slimline KS-2 speakers with 12" woofers. Later I've got another basket case Fisher 500B thats in similar condition what I started with on my KX-100 and KM-60. The 500B will probably be next years project.