my google fu is weak

I have just lashed out the princely sum of eight quid on something from eBay.
It seems fine, I just want to know what it Really Is!

It's a guitar amp (practice combo) called an ARIA PRO II TWIN DRIVE II
which has the model type of "ATG 35R" on the back (and power consumption 30W).

I'd just like to know more about its innards.
But I find nothing...

Help me nothing-better-to-do-web, you're one of my only hopes!