I also grew Fort Portal a few years ago. It's not quite as green as the Richter's picture leads one to believe, more of an olivey color. Alas I no longer have it (at least I don't think I do, see below). It produced pods quite readily for me. Only problem it, it also grew incredibly short. And that's why I don't have it anymore it was SO short that the chipmunks literally were able to stand up on their hind legs and one by one pull off and eat every single solitary pod as it got big! So I never got a chance to get seed back.
That being said, I have had experience with some of Joe's other beans he offered through Richter's and have had good results. In particular I got good results from the Bantu bean, which is actually very, very similar to the FPJ differing mostly in seed color. FPJ is green (mostly again see below) Bantu is occasionally the same shade of green, but is more often shades of tan, maroon and purple. I planted those last year (in pots on pedestals this time, to keep the critters off) and was favorably impressed. For a bean that originates only half a degree from the Equator, Bantu is surprisingly cold tolerant, as is the Fort Portal Mixed, which despite the name is not all that similar to FPJ; being more of a kidney bean (and probably not actually mixed). I actually got a decent amount of seed off them (though not quite enough to share at the moment).
Only odd thing concerns the seed colors. While the Bantu that went in were all of those tans and browns, all the seed that came back is the exact same color; bright pink when it came off the plants, lavender-purple when dry. Same thing happened with the Mixed; tans browns and blacks went in, bright purple alone came out. So Fort Portal Mixed may be more accurately describably as Fort Portal Variable in Color".
Actually, there is a tiny chance that there is some FPJ in my stuff as well. When I got my two packets from Ricters a couple of years ago, there were actually two non green seeds in them, one purple, one steel blue. I contacted Ricters to make sure I had gotten the right stuff (between that and the difference in color, I though they might have sent me Bantu by mistake (which I hadn't tried yet, and so had no idea of the appearance of) They confirmed I had gotten the right stuff, but also said they were rouging out any non greens from the packets they still had to make sure no one else got confused (so theoretically somewhere in their offices could be a little pile of Fort Portal Not Jades lying around even now that the stuff is sold out). However I didn't toss out my off type pair. The blue one I misplaced (pity as I have never seen another bean that color either) But I managed to hold onto the purple one and it got planted at the same time as the Bantus. Problem is I also got planted in the same POT as the Bantus, and since they look so similar I have literally NO WAY to know if it was one of the ones that survived or produced. Out of the 30 or so beans planted 9 lived long enough to make one flush of beans (kind of normal for the Joe stuff from Richter's it's getting old and they don't regenerate it) and one of those lived on to make two more flushes before conking out. The long lived ones MIGHT be the FPJ (or since it's purple Fort Portal Amethyst) or one of the bantus, no way to tell.
This year I have Three FPM's still growing (the wind chewed the hell out of them) and I'm trying my hand with another of Joe's beans, the Mottled Grey which, I think Richers still has a tiny amount of (tough germination for thiers currently stands at about 25%, fair warning)