Mongo Erectus is Fredrik Djurfeldt from Severe Illusion , Instans and Knös doing cover versions of classic commodore 64 music.
The name Mongo Erectus was originally used for music made on the commodore 64 itself, in a lame attempt to contribute to the demo scene as early as 1989. One tune from that era can be found in the High Voltage Sid Collection (here: ...DEMOS/G-L/Hangover_part_3.sid).
Yes, I do live shows every now and then. Send me an email if you have anything to suggest. I can be quite reasonable at times.