-Upgraded Preamp to NOS Mullard
-Upgraded OT to OEI Output Transformer
-Bias was set properly
-Changed to EH/Sovtek EL34's (the newer ones)
-Disconnected one leg of the channel 1 treble pot cap
-Disconnected the Negative feedback loop from the 8ohm tap and connected it to the 16 ohm tap
-Changed the resistor in the negative feedback loop to a 47k (from 100k)
 
It now sounds much closer to a later plexi or early metal panel amp. The tone is more thick (especially with a humbucking guitar), but its still got a nice lead voice. Ted gave me a list of other mods (all cap/resistor changes) that will get it even closer to the early plexi/1986 sound. I haven't decided to do those yet as I'm really enjoying it as it is. 
 
If you don't have the $ to upgrade the tubes and OT right now, the following changes will be the most effective and will cost almost nothing.
-Set Bias properly
-Disconnected one leg of the channel 1 treble pot cap
-Disconnected the Negative feedback loop from the 8 ohm tap and connect it to the 16 ohm tap
-Change the resistor in the negative feedback loop to a 47k (from 100k)
 
Good Luck,
 
Erik