Karl, how far have you gone in your investigations into not seeing gains? What factors have you manipulated to try for gains? I'm certain you're frustrated after all this time invested, and I'd love to help try to sort out the issue.
Let's assume the air part of the equation is not the issue - with compression that high and uniform, I'd be pretty comfortable leaving it alone for now, since compression goes nicely with vacuum. That leaves fuel and spark.
Your engine, if I recall correctly, has 2 spark plugs per cylinder. Have you over-gapped them? I've seen suggestions that there are 2 coil packs for those 8 plugs, and the wires from the 2nd coilpack can be re-routed so that both plugs in each cylinder are firing at the same time to more fully burn the air-fuel charge, rather than sparking at ignition and then again to burn what's left in exhaust. have you tried that?
I'm not an expert in chemistry, but it seems that you're the only person around here using acetone and toluene in addition to aspirin as a fuel additive. In fact, this website
suggests that you may be shooting yourself in the foot. Could that have something to do with it? The person who introduced "the remedy" here was pretty clear in stating alcohol for aspirin, along with hydrogen peroxide; he also alluded to using ibuprofen in place of aspirin for its higher hydride content. Is it possible for you, on your next tank, to use high-proof everclear or medical grade isopropyl (rubbing) alcohol with food grade hydrogen peroxide in place of acetone and toluene with aspirin in your tank? I'd try this first, personally, and then re-gap and wire the plugs if you saw a result.