i had one of those as a nano tank - now its my quarrantine tank for a 40gal SW.
the hood is in 2 peices front part holds lights and hatch for feeding access / back part holds the trickle filter.
Mine had 2 x 20W tubes in there when i bought it - i ripped that out and put in 2 x 55w PC's that worked great but ended up drilling a load of holes above and each side to allow the heat to escape a bit.
Im sure Maidenfan had a 620 nano too.... I'll see if i can find the links and post below