All too often folks show up here with tasks like this that can simply never be pinned down.
There's a dropbox where one can download sketches - what I do is a simple pencil sketch, and then snap it with a camera. Here's an example:
Notice this was purely a hand pencil sketch - but it has all the dimensions and whatnot. The tolerances are implied in this case, with the three decimal numbers being within a thou, and the two decimal numbers within ten thou. It gets the idea across.
In your case you sketch up what you want, dimension the things you need done close with decimal, and the ones you don't need close as fractional, for example. Or you could put a note saying 'all dimensions +/- one quarter inch, except as noted' or something to that effect.
The fact that you put a dimensioned sketch available puts you in an entirely different group for folks to comment on.
Jim