I‚Äôll show the scans first, and below I'll explain the ‚Äúpre First Day‚ÄĚ of the heading, and why it‚Äôs in quotes.
The days of issue of these stamps were 31st January 1938 (2d and 3d) and 21st November 1938 (4d and 5d). As you can see from the scans, these covers are cancelled with postmarks of the Up Special Travelling Post Office dated the day before in each case. Were these pre-releases then? Almost certainly not, as it happens.
The practice in Travelling Post Offices was to set the date in the handstamps at the start
of the journey, and use them throughout without change until they reached the final stop -- either as a backstamp, or to cancel the stamps on the relatively few letters posted on the train when it stopped at a station. For those TPOs that started their journey before midnight and completed it after, that meant that in the latter part of the journey they were cancelling stamps with the date of the previous day.
Normally, of course, this made little practical difference. However, it was the practice for new stamps to be placed on sale at midnight at the Trafalgar Square post office (and possibly some other big offices). So some canny collectors who knew how the TPOs worked would buy them as soon as possible, hop into a reasonably fast car, and meet one of the five such trains coming into London (which is what "Up" generally meant in British PO parlance when applied to TPOs). By posting them on the train, they would get a postmark that was apparently
from the day before issue, but was in effect an unusual First Day postmark.
In 1953 the Post Office took steps to adjust for this -- on new issue days postmarks with the actual date were used from midnight on the new stamps, with an "AM" time slug to distinguish them from the following night's run. In 1938 though, that was some way into the future.
The FDCs are catalogued ¬£95 and ¬£60 as plain covers with normal operational postmarks in the SG Concise (2007, although I don't think they've changed the price recently). What we have here are two with really rather unusual operational postmarks
, albeit with some small faults (bends etc) as can be seen in the scans. I can't remember seeing a pre-war example of such a "TPO pre-FDC" before, although then again it isn't something I look out for specifically -- these two just happened to come to hand.
Price is ¬£40 inclusive of normal postage and packing to anywhere. If you express a wish for interesting stamps on the envelope I'll do my best to use some (although you'll have to take pot luck on what the current British Post Office do to them -- your chances of getting something collectable are not great). Payment via sterling cheque on a UK bank would be appreciated if you can do that (contact me via email for address), otherwise Paypal to mauriceibuxton (AT) yahoo (dot) co (dot) uk.