[sowise]

I was specifically refering to the upper mounts the lower mounts are "potentially" possible as you describe by either opening up the flange mounts or grinding down the spindle depending since I have not checked fitment yet.

I will try to get the measurements but I am not sure exactly how they take them. There seems to be some slight differences in the overall triangular shape in the different mounts for different vehicles. The bolt locations I will probably measure from center of the hole as well as diameter of the center hole. I am supposed to make a trip to a salvage yard soon and have thought of making a quick template so all I have to do is throw it into place and see if the mounts line up.
There are some after market caster/camber rear upper mounts that look very close to being able to fit up or being very easily modified to fit. Just not sure I want to put money towards that yet if they don't or won't work. I checked some of the rear STi pink springs that are supposed to fit a forester and bottom spring would fit the strut but the top of the spring coil is smaller than our upper mount shield so just the shield mount alone may be possible to replace with a forester (haven't checked yet).
Edit: Ok I didn't get the measurements because I was too lazy after work but I did mount the stock spring rusted top shield and stock svx rear mount to a 2000subaru legacy sedan strut. The strut is shorter doesn't have as much shaft length which causes more spring compression not sure how that would affect over all ride but would definitely lower rear. As previously mentioned the flange mounts are just slightly too tight maybe 1/8" at most so very possible to grind the spindle mount if necessary. If I get a wild hair I may pull one of my bilsteins and see how that fits or if it fits any better. Still going to look at forester top shield etc.
Side note: PnP and ceramic coated intake and throttle body should be arriving any day now, SS exhaust manifold shipped by end of the week hopefully. Subaru parts.com is shipping the rear WRX/STi back plate for 2 pot brake fitment (hopefully). Other things still in the works.