GarageBoy
Well-known
Fx39 - that's a Crowley formula, right?
Skiff
Well-known
Yes, that is right.
Due to Geoffrey Crawley's own words it is "his best developer".
He was at ADOX to implement the FX-39 production there, before he passed away (R.I.P.).
ADOX recently even improved the formula further: FX-39 II has an improved shelf-life.