Wrong again RAAArty!
I know you love your conspiracy theories but the answer is rather more mundane I’m afraid.
Magazines have production schedules and these include print and publication dates. Obviously monthly magazines are not all published on the first of the month shown on the cover otherwise the printers couldn’t cope so they have slots throughout the month and are usually actually published before the nominal month of issue. These dates are usually around the same time of the month allowing for weekends and holidays etc. So Marine Modelling and Model Boats were not published at the same time of each month. However, as you might have noticed, Model Boats publishes 13 issues annually whereas MM only published 12. So the publication dates for Model Boats in the early part of the year are gradually advanced month by month to make room for the Winter Special issue which is published at the end of October.
July Marine Modelling International went on UK sale on the 4th Thursday of June. August MB went on sale on the 7th July, UK subscribers getting theirs around 5 or 6 days earlier so there was time for readers of both magazines to take up the offers in the standard advert.
Model Boats is indeed sold worldwide, much of it by subscription, but all copies are actually printed in the UK so there will inevitably be a delay in getting it 12,000 miles to Australia. If this is a problem then you could of course have it on publication day, maybe earlier if you were to take out a digital subscription. It would be totally impractical for a small company like MyTimeMedia to have multiple printing contracts around the world. Most sales are in the UK.
Anyway I can set your mind at rest on another theory that you may hold. The world is NOT flat and you ARE upside down.
The internet is a wonderful thing but it does unfortunately facilitate people adding 2+2 to make 5 and sharing their ill considered revelation with the rest of the world.
Colin