[78-L] Single Sided records in Great Britain

[Matthew Duncan]

Hi all
 
I have several single sided gramophone records on British labels ... most of these are pre 1910 recordings and all the ones I have up to now are 10" or 12" discs. I have double sided HMVs from 1910s to 1950s.
 
One exception to the single sided lot is a 12" HMV on 2-022016 (matrix Cc1891-4) by Chaliapine dating to 9th October 1922.  I guess this was issued in the Spring of 1923 (approx).
 
I have read that HMV made most of their single sided items in the earlier period of thier existence but continued to issue new single sided records (although not very many compared to their double sided output) until electrical recording was installed by the firm (early 1925?).
 
Then, I have read on the internet that as soon as two single sided items were reissued as one double sided item, the single sided items of old were removed from the catalogue.
 
My questions are...when were the last single sided HMVs??  And...could it be true that some single sided records were available years after 1925 and not deleted from the catalogue very quickly?
 
I imagine many would have disappeared from the catalogues in the early 30s due to electrical re-recordings of many works and also the depression would have 'streamlined' all company activities.
 
Regards
Matthew