Welcome John
It is almost certainly an International One Metre (IOM). Since becoming internationally registered in 1988 it has grown to be the most numerous rc model racing yacht class.
From what we can see in the photo, the rig looks good.
There are a number of plans for home build IOMs with Sarik Hobbies and others from a variety of sources if you Google.
There is some freedom of design in the hull, for example the beam is not controlled but the rigs are effectively one-design and have to made to close limits. The rules are the "closed" type which means that something is only permitted if the rules say so.
They are great boats to own and sail and I have a later model called a Topiko. Currently having a bit of a refit.
Have fun
Tim R