Even if the amp originally came with the push/pull, I don't think you can assume the amp has been "blackfaced" based on the lack of push/pull switch.  As I understand it, BF'ing a Fender amp involves a few changes, and not every tech does them all.  Some techs would not see any value in replacing the push/pull with a standard pot, since there's no sonic difference between using a standard pot and using a push/pull pot with it pushed in.  For that matter, a blackface Twin didn't have a master volume, yet people will "BF" a Fender and leave the MV pot in place (I've owned two such amps).  I've heard debate as to whether there's any sonic difference between bypassing the master volume pot vs. going through the pot with it turned up all the way.  I A/B'ed one of my Twins with the pot in the circuit and turned up vs. bypassed.  I couldn't hear the difference.
Unless you know enough about the amp designs to safely go in there and look at the components and how they're connected, I think the only way to tell the extent to which it might have been blackfaced is to take it to a good tech and have him look under the hood.  If you like the way it sounds you might decide not to bother.  Having heard stock SF Twins, BF'ed Twins and partially BF'ed Twins, I think they all sounded good, but none of them were necessarily clearly superior.
Congrats on your new amp.  :)
-ScottStatistics: Posted by cheepaxes — Wed Aug 12, 2009 2:58 pm
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