I had corresponded with Dave over a year ago, and he replied:
"There will be upgrades and mods for the Fatso in the future. The first mod
will probably be announced in May  and orders for the modification taken in
June or thereabouts. Keep looking at EmpiricalLabs.com for more information
under the FATSO section."
What exactly does the British mod do sonically?
Does it change it's behavior when using different ratios?
It speeds up the attack and release in a very strange way by re-biasing the envelope circuitry. The intention however was to model the LN1176 with all 4 buttons in. It turns 1:1 into a new ratio, but... you can also apply the re-biased envelope to all the ratios for lots of wacky sounds.
I recommend keeping the attack WAY under 5 (1 - 3 more often.)
You can make it distort musically, or you can use it subtly by slowing the release so it doesnt modulate every cycle of the low frequencies.
I promise it will offer a lot of new colors to your Distressor.
"There will be upgrades and mods for the Fatso in the future. The first mod will probably be announced in May  and orders for the modification taken in June or thereabouts. Keep looking at EmpiricalLabs.com for more information under the FATSO section."
OOps! Would you believe we are waiting untill we hit SN 1001? Or that I FORGOT? Or umm, that the dog ate the schematics?
Sheesh I am sorry! Im not trying to be a smart ass becuase I honestly thought we would have mods out there now. The truth is we do have many mods in mind (and more) for the Fatso down the line. One of the first mods will be a ratio that replaces the current GP ratio, since apparantly NO ONE USES IT! We have a few choices already and will be offering them soon but several things have been going on that keep us from releasing information on FATSO MODS.
1) We got hugely back ordered and couldnt initially keep up with the orders at all. We have recently hired a technician who keeps them on the shelves. No Lie!
2) We moved our whole facility. We bought a building in the winter of 2002 and unfortunately it took months of fixing up and lots of money before we finally moved in Aug 02.
3) We are planning a beta test as we speak of the new compressor, but its pretty finite and will take a while before we narrow down which ratios and shapes we will use. The Fatso has the ability to give a huge range of attack and decays inside.
4) We have been through Hell and Back because Clarostat quit making the molded carbon pots we have been using for 7 years! We chose these pots because they had been around for over 30 years and thought they would be around for another 30. This has really jammed us up and brought new problems upon us. The old pots were TRUE logarithmic and verrrrrry smooth down below 4 on the knob. You will see other posts on here from people whose pots dont match perfectly (something that doesnt EVER HAPPEN!) and about having to work down between 1 and 3 on the input pot. These are a result of the discontinuation of those pots. I could go on but Ive already ranted enuf, and made plenty of excuses.
Please bear with us and sorry for the delay. But rest assured, Your Fatso will Have New Tricks and Sounds Coming. Thanks for your patience, BOB.