Tony,
The 'broken Eighth' grey 'frame' sorrounding and crossing a Unit colour patch was adopted by several units that 'survived' the decimation of the 8th Aust Inf Division. However, it was never an officially recognised form of the Unit colour patch, and was adopted more or less at the whim of each Unit's CO. The form is not listed in official orders, and does not appear in the Army Colour Patch Register, but is mentioned in 'Color Patches and Ribbons of the Second World War' published in 1946.
Regarding 25-pdrs, the problem of identification is in which number do you use as the identifier? Until the registration scheme for artillery was introduced post-WW2 (and I'm yet to find a comprehensive list of these numbers!), each major part of a gun was identified by a number, eg barrel, breech, carriage (on a plate rivetted to the saddle), saddle, and so on: all parts that could and were changed when worn out or damaged. Barrels, for example, were routinely changed each time the requisite number of EFCs were reached. Breech blocks like wise at each third barrel change, and so on.
In the case of a saddle, a worn saddle, following refurbishment, could end up on another carriage. The gun log book can give a clue or two, but the majority were destroyed when the weapon left service.
So I suppose the best way is to register what is on each gun now, in the knowledge that this is most unlikely to have been the original factory assembly.
I wrestled with this 'problem' many years ago (when I was working on 'Field Artillery 1939-1945') but never really solved the dilemma satisfactorily, finding it well nigh impossible to trace a particular gun's lineage from factory to present day. I still collect the data, but drawing meaningful conclusions is the problem.
Comments??
Mike C