Dual Rec serial number question

[all_star_ben]

So I purchased this dual rec yesterday for 725 from our local shop. The previous owner had passed away and the family, in order to pay off debts, sold all the amps he had collected (a couple dual recs, a Bogner, Mark IV, Road King and some others). Anyways, I tried finding the serial number to date it but all the numbers I found weren't in the format most dual recs are. The numbers I did find are these:
166B10
562105
40-16620
166-1029
EIA606-343

Any ideas? thanks!!
-Ben




Uploaded with ImageShack.us



Uploaded with ImageShack.us



Uploaded with ImageShack.us

 

[deeman]

look at the pics in this thread http://forum.grailtone.com/viewtopic.php?f=24&t=64956.

The number should be on top of the chasis near the power cord.

 

[all_star_ben]

surprisingly I had come across those pics but this what that location looks like on my head:


Uploaded with ImageShack.us

looks like the serial number was removed?

 

[O==00==O]

Yep it was removed. Maybe it was stolen? Nah...

I also noticed the Ground switch looks like it was replaced by hack. It's not the usual black covered toggle, and there's a scratch marks all around it like someone used pliers to unfasten it.

In any case, it's not one of the Pre-503 units, it has the same OT as my '93.