Because we get asked from time to time. here is a quick summary of the differences:
The original Deliverance is a single channel amp with no effects loop.
Deliverance II is also single channel but with an added SOLO mode and the associated foot switchable solo volume control and foot switchable FX loop.
Deliverance II+ basically has more clean headroom. Now the GAIN II control disengages in LESS mode for better control over clean voicings and improved ability to balance between clean and OD modes.
These model changes required major internal layout revisions making it too expensive and time consuming to offer these as upgrades to previous model versions.