It might be worth investigating,  
It's a new seller, vague info...
 
http://www.ebay.com/itm/mark-1-1973-mesa-boogie-amp-/280844948925?pt=LH_DefaultDomain_0&hash=item4163a9d5bd#ht_500wt_1076
 
 
 
I'll check out some old pictures online etc.
 
thoughts anyone?
 
 
(edit: I see it's also listed on the boogie boards)
 
(Message edited by elwoodblue on March 18, 2012)
 
(Message edited by elwoodblue on March 18, 2012)

I see someone is taking the plunge,
 
If it's legit,
 it's been all over this world

My bandmate was very interested and discussed the amp at length with the seller. Sadly, he has since decided not to sell the amp (the high bid was from the seller, who I guess didn't know how to retract the auction).  
 
Seller says he was a kid in the extended Dead family back in the day, and was given chance to take some items from a band storage space a while after Jerry died. We're satisfied it was definitely a Garcia amp. Now guy says he will never sell it. sigh ...

Thanks for the update,
 I sensed something was up with the bidding,and I don't blame him for having second thoughts.
 
  I'd love to know what mods/speaker/tubes/etc. were done.
  I've read Jerry used the Mesa's like the twins (preamp out to MC2300), I guess I should look for mics in front of the mesa in gig shots.
 I have a '76 MK1 that I'm trying different tubes,JBLs/Altecs,etc.  
 
 
  If he does sell it I'm sure he could get more than 3 grand with the right exposure.
 
rock and roll,

While we're on the subject:
http://www.jambands.com/news/2012/03/17/jerry-garcia-s-guitars-artwork-and-harley-to-be-auctioned

There alot of varied artifacts in that auction.
I might be able to afford the 2 guitar picks,
(I'd want to use them, so I guess I'd get a frame and picture as a bonus)
 
http://www.bonhams.com/usa/auction/20158/

Elwoodblue,    In some of the old Mesa's ,they sometimes used a 12ax7 preamp tube substitution called a FETRON in one of the preamp stages. It would look like this ;DO you see one in your amp?

I'll look tonight,
 I have a couple nice old 6550 power tubes,
the Mesa wants a quad...so I was thinking I could try them in the outer(or middle)  sockets ,
 and use a 16 ohm Speaker instead of an 8 ohm.  
 
 thanks for any help/good info...I didn't know about the FETRONs

 
Perhaps the 6L6's would be safer

Yeah..you are quite right, I'll save the 6550's for the Sunn.  
 
 No Fetron on this one. It has 5881's in it now,
but I don't know if it was  biased properly by the previous owner.  
   I have a new set of Mesa 6L6 STR's rated at 10, so I guess they are on the hot side.
 I have three old westinghouse 6L6 GC's (what happened to the fourth??).
 Might be time to learn to bias my own amps ,  ...[self-biasing?].   ; )
 
 
 I pulled out the old G-100 celestion and have an Altec ready to install...I might try a D131 too,
they are getting to be a favorite of mine.
 
 The amp as it was , had a harsh upper end that I'm hoping to smooth out ( I'll try some different pre tubes too), and getting to know the amp better in the process is a plus.
 
 thanks for the sound advice !

You are absolutely  welcome ,  
 
 Sonic Regards ______

Boy, the Mesa amps I have had were not really that sensitive to what tube was in there in terms of brand or vintage, due to the amount of gain they had designed into them. Various speakers made a change though. I always liked the stock Mesa C-90, even more than an EV.
 
JJ makes great tubes that they like. I just use Sovteks in the power section as often as not.

You might find a difference in sound between the Chinese power tubes and the Russian ones . The envelope vacuum has been found to be higher on the Russian tubes .

There are certain tubes I just won't use, of course; Chinese, Yugo, Groove brand. The fat bottle Mesa 6L6 are one of my favorites but hard to find. The new Tung Sol seem good.

David Nelson plays an old Boogie that looks like that one, but I don't know which model. Love his sound, with the Tele and b-bender....