Hi Chris,
Sorry you missed the issue but it is normal practice in the publishing industry to bring magazines out in advance of the nominal month. In the case of Model Boats the dates can vary from month to month as there are 13 issues in each year (included in your subscription) so the publication dates have to be juggled about a bit to allow for the insertion of the Winter Special in November.
However all is not lost as back issues are available from a number of sources including this one:
**LINK**
I would recommend that you get hold of the June issue and not try to freelance the model as in addition to the plan there is a lot of other useful building information in it.
Good luck with your build and post some photos on here if you can.
Colin