Modern thinking is almost certainly towards computer modelling of weapons release, and then using your few available test assets to validate those computer models.
Not cheap or easy, but probably the best reasonably achievable under your constraints. Finding somebody whose modelling of such situations you'd trust may be a challenge. You could try Qinetiq in the UK, if you have sufficiently deep pockets. A good aeronautical university would probably be cheaper - possibly Glasgow or Liverpool Universities in the UK have this sort of capability. PM India-Mike if he doesn't chip into this already, he is in that area of research and might be able to advise.
G