Podolia Tridents / Podillia Tridents - help please

A dozen years ago, I had far too large a stock of the Tridents of Podilia / Podolia, most of it from remainder lots of the Vyrovyj collection. In addition, I had some Podolian postal history material from the 1915-18 period and the 1921 - 25 period. So while my younger daughter sat and revised for her school examinations, I sat and constructed two large collections: one of Podolia trident sub-types; one of Podolian postmarks 1915 - 25. The latter collection showed cancellations from about 140 offices.

I recently examined the postmark collection in order to establish the date around which Tridents came into use in Podillia. I have no examples of postmarks on Podilian tridents earlier than 7th September 1918 - and that cancellation, from MICHALPOL, is on a favour cancelled block. I then have postally used examples on the 12th (VINNITSA ZABUSHE), 16th (BRASLAV),ZHMERINKA (20th), KRIVOI ROG (26th) and SNITKOV (28th).

Unoverprinted stamps clearly continued in use for a while alongside trident-overprinted stamps. The last example I have is from SHATAVA on 21st September,and t the penultimate use of unoverprinted stamps is at DUNAEVTSI on the 8th. These late uses are of stamps on Money Transfers or fragments of them, so they are not examples of private individuals using up stamps.

So I conclude that in Podolia / Podillia trident-overprinted stamps came into use in September 1918 and by the end of the month had largely replaced non-overprinted stamps.

Am I right? Does any reader of this Blog have a clear cancel on a Podillia / Podolia trident before the beginning of September? You can scan me a copy at trevor@trevorpateman.co.uk. Thanks in advance!

POSTSCRIPT 23 AUGUST 2010: In his Ukraine Handbook for Podolia, Dr Ceresa illustrates two Money Transfer Forms sent from LETICHEV POD. on 27.8.18 with mixed frankings of overprinted and unoverprinted stamps. This pushes back the date for introduction of Podilian Tridents into August 1918. That is coherent with the August date given for Trident introduction by Bulat in his catalog for several other districts: Kyiv (page 7), Kharkiv (page 38), Katerynoslav (page 46), Poltava (page 74). He does not give a date for Odesa or Podillia.