I decided not to progress the trade skill quest I'd been stuck on (general lack of grandmasters!) earlier, mainly due to a suspicion that the "gnombies" would be lurking-in-wait around the fae newbie bank! Instead I picked up a toon (necromancer, figured I could be in zombie+moppet mode and sneak by!) that had started the Advanced Journeyman quest in the Sinking Sands.
In making the Bert's book recipes I had to use thaumaturgy. Thaumaturgy at my alts level (54) is bugged in the same manner that the armourers reaction arts are bugged at certain levels; i.e. a successful reaction art does not guarantee a successful set of results.
I know that the QA folk and the devs have had a hard time replicating the armourer bug (still wish I had their RNG relationship!) so reporting it here in case they can use thaumaturgy & this quest to see what folks have been complaining about.
I have /bug'd this in the past btw, so no-one needs to advise me to do that. 