Well, after a 'life event' intervened last week, I have finally had a chance to come back to this thread and it is a veritable gold mine! Thank you all so much.
The little asides (Mrs X wonders why it was called 'hour') are gold to me in injecting more than a whiff of authenticity into the novel.
The feedback on the drop timing and method for the Argosy is brilliant, thank you so much @ICM.
One of my get-outs is that this is a trials unit and therefore not everything was done as it would have been on a squadron. The Argosy gas bombs are based on a real event, however. My father recalls the trial - they built a mock village at Porton Down and then dropped them with mannequins dressed as civilians with patches recording the spread of the gas (tear gas my father thinks). At some point I will visit the National Archive and read up about this and other trials in more detail.
I have a couple of follow ups and one new question to post below. Thoroughly enjoying the gen, thank you all very much:
@Pontius Navigator
@ARCHIE1
@Brian 48nav
@tlightb
@oxenos
@ICM
@Cornish Jack
@fareastdriver
@charliejuliet
@Tengah Type
@Dougie M
@Timelord
@Retreating Blade
@spekesoftly
@rlsbutler
@alwayslookingup