Levinson 331 leaking black tarry material


My trusty old levinson 331 has been collecting dust x 2 years. It was left unplugged in upright position. Last week when cleaning around it, i noticed thick black tarry liquid was spewing out of the power cord socket. I removed bottom panel and found more of it on the inside of the rear panel where the connectiins for power, rca, communications link. I was guessing electrolytic fluid from one of the caps but i doubt it. Gravity shoyld have pulled the liquid down onto the bottom panel right??? Not a drop there. I remived the top panel also but that did not reveal anything. No rubber or plastic melted from top panel. Or gaskets. Is there an easier way to post pictures? Not sure i still have photobucket.
chenglo1
Thanks for all the help guys. Ill post again once figured out. Teo_audio, i appreciate the detsiled response which makes sense. Ill also email Levinson to see if any of the veterans are still there. 
Sorry my photobucket acct doesnt exist anymore. Is there any other way to upload pics to this forum?  Its been a while since i last posted a thread.
Dweller, room temp about 70 to 74F and 30 to 45pct humidity. Im betting its power teansformer tar then because it sure feels like it! Feels like the tar tgat gets on ur car and tough to wash off! I got some on my fingers.

Caps were all replaced by one of the great contributors here (Abe) and myself. 

Will post pic soon if can get back in photo bucket. You guys are great! Thx.
The power transformer is sometimes "potted" in tar to stop noisy vibrations. What temperature was it stored?
If it has a slight ammonia smell, then it might be electrolytic fluid (dried up) from one of the main power supply caps. It tends to be quite easy to smell. Much in the direction of a stale urine smell.

However, a quick look at an open chassis of this amp illustrates that it is likely the black glue material they used around the periphery of the plug and metal plate interface. It may have originally been viscous/tar like... and not like a solid epoxy, and might move around from heat exposure and time.

If it’s been moving around, then this amplifier might have had a little too much heat exposure while in storage. Capacitors age from heat, whether the capacitor is in use or not. The scale/chart for the aging of capacitors from heat is not linear, it’s almost exponential. It is a notable part of why thermal management for audio gear is such a big deal.