Nice Phil.
I note your set of hat/cap/collar badges without the scroll. While at the AWM earlier this year chasing up correspondence on RAA badges I came across mention of the AC of Sigs badge in Military Board Circular Memorandum No 337 dated 19 June 1930 which amended the already approved design to state that the motto Certa Cito was to be added in a scroll around the foot of the badge.
I don't recall now whether this also related to the collar badges but the Illustration Numbers for both left and right collars, and the cap badge (No 1367) as supplied for the potential tenders suggest that the same design, and thus the motto, was used for cap and collar. L. Orbuck of Church St, Richmond, Victoria, manufactured both cap and collar badges.
The original approved design for the AC Sigs badge as authorised by MB CM No 200 of 10 April 1930 was for Mercury surrounded by the circlet with Australian Corps of Signals (The article in the Mercury dated 14 May 1930 describes it as a garter but this doesn't appear to be correct does it) surmounted by the Imperial crown. No scroll and motto.
The following link is to the file relating to correspondence from Signals units regarding the design of the badge during 1929-1930:
http://recordsearch.naa.gov.au/Searc....aspx?B=367409
It might be possible that some units of Sigs were quick off the mark in using regimental funds to order badges based on the first authorised design and these were supplied and worn until the design with motto began to be provided at public expense.
I note that sergeants of 6 Fd Bde AFA here in Hobart were wearing the old AFA collar badges on their privately purchased blue uniforms in 1930, perhaps on the same principle because collar badges for other ranks of RAA/AFA/AGA were not authorised until June 1930 and AFA/AGA officers collar badges, although approved at the same time, were not supplied at public expense.
Cheers, Keith