JAD started around 1994. Mike named the company after his kid's first initials; "J" and "A" and threw in the "D" from their last name. Short, sweet, simple and novel ideas are sometimes the best. A few chop-sawed frames, good timing with the goofy design and a catchy name was all it took.
Long story short, the ORIGINAL company made 200 racing frames in both the 20" and the 24" versions. However, not all of them were the same. In fact, very few were built to the same specs. Partly due to...
A ) the frame's evolution from 1" to 1 1/8" headtube designs.
B ) constantly changing dropout designs.
C ) the addition of the brace from the "tube" to the BB on the later model frames.
D ) various cable stop locations.
E ) and finally, optional paint schemes.
I do not know the number count but JAD also made a freestyle/flatland frame and fork combo called The Sherman. These frames had and "enclosed" dropout design as opposed to the groove cut on virtually every other frame in the known world. Another major difference came in the chainstay tubing. Larger ovalized tubes replaced small round tubing for a stiffer, stronger frame. The Shermans command a higher price due to the low number count. These too had variations between them but to what extent? I can't say for sure.
12 mountain bikes were also made and I've been trying to get my hands on one since Mike welded the tubing. They certainly aren't worth as much as their owners think they are when I've tried to buy them in the past. I will admit to a lot of things including; impulse buying, paying too much just to have it and impatience but I am not stupid. So, I will continue looking until that fateful day arrives.

Lastly, they made a handful of parts. Their most popular part was the JAD cranks. These too went through multiple generations.
Prototypes/true 1st gens) pierced and welded chromoly cranks similar in design to S&M Alberts.
1st gens) Aluminum crankarms with a milled backside
2nd gens) Aluminum crankarms with a milled backside and plates that screwed onto the backside. These are the most common.
3rd gens) Aluminum crankarms with a series of drilled depressions for saving weight.
There are a few others out there that may have been one-offs such as the magnesium cranks that are uber-rare.
Other parts are extremely rare but include handlebars in both pro and cruiser sizes, oddly shaped flatland handlebars, super high flanged hubs, freestyle coaster brake low flange hubs, stems, forks and the standard T-shirts and decal sets.
There is a ton of other info as most of their stuff changed with every batch. Warn owns the company now.