Not sure if this helps, but quite a few members here like ESPO. Stock height should be available if you give them a call. Unless you are going for Gold certification or the highest level of restoration, I am not sure that I see the benefit of hunting old springs. If that were the case, use the EPSOs for a spell and have the old ones rearched, refurbished and put them back on.
Definately a thought....I found a really nice set on the parts car that I bought but found that the parts car was pretty damn nice and 100% complete so the parts car became a project car......will let you know if I make any progress next time out on "Grand".