I would model it as .748, not the stock material size. The dim on the drawing can be .747-.749
.748 +/-.001 is OK
.750 -.001 is my first choice
.749 / .747 is my second choice.
The tolerance zone does not have to include the nominal shaft size, and doing it the way you propose makes it much easier to understand during a design review. Also, it is easier to compare to fit specs, which are written that way.
Any of the ways Mike mentioned would be fine. I personally prefer the model to be in the middle of the tolerance zone because there is a chance (even if it is slight) that a CNC machinist might program the machining based off the model and not look at the tolerances on the print. Of course you could still reject the part if it was made .750 but you might save some hassle if the model reflects how the part should actually be made. Also if you ever use interference detection in SW then it is better if the model matches the actual dimensions.
In case you need to know how to do it, you can just do bilateral tolerance and put a negative dimension in the + area.