How to realistically model propeller static thrust?
This basically depends on the prop loading and RPM. If you are not satisfied with the momentum disk theory based results then the next step would be to use blade element theory based calculation.

If I were you I would certainly run few test cases with a known propeller geometry by scaling the propeller. One of the easiest way I can think of doing this is to use QPROP from Prof. Mark Drela at MIT. This is a free software and on top of this it is a command line program which is very well suited for this kind of an activity because all the parameters could be changed on the go, preferably via a bash or python script. 

HTH