Answering my own question, the answer is in the T&Cs…
“The time it takes from placing an order to send out your purchase varies. We hope
to send Certificates and Merchandise within 10 days of orders,”
I received this recently as part of an order acknowledgement. My last order did not need any engraving or processing, and it was three weeks or more till it arrived. I don’t actually know how much of that time was shipping or perhaps even customs? I think the answer is that you probably can’t plan on too specific a time frame. This business model might not work as well for Amazon, but as a fund raiser for SOTA, staffed by volunteers, many thanks to them all for their efforts. And for giving me a great way to contribute just a little bit myself.
Your order placed on ??th Month Year 21:46 will be processed as soon as possible, however SOTA is run by volunteers so certificates and merchandise may take up to 10 days to process (work and family commitments take priority). Trophies can take up to 28 days for engraving and other processing
The postal service to the USA is normally about 5 days but I have known it to take up to 28 days, other countries may vary. You also have to factor in my availability to do the work which is why these timescales are stated. To make matters worse orders do not arrive in a steady stream but are quantised usually one lump after the monthly report and then another in the last week of the month, the result is that I also quantise my efforts!
Trophies take longer because they have to go to an engraver for hand engraving of the callsign and any other information, the lettering has to be infilled after this and then there is the packing and taking to the post office for despatch.