[Techman]

Unfortunately I have to agree with Edward that you've no real choice other than to mount the amp on its side. I don't like amps on their side. but the other option is to extend the control panel, and you can trust me when I tell you that you'll never do this and make it work properly in a month of Sundays. When I was a youngster, I build a radiogram (well actually it was just a gram in a homemade radiogram sized case) and mounted a homebrew Mullard 3-3 in the bottom of the case. I extended all the volume and tone controls to a plate in the top of the cabinet and spent ages sorting out instability causing HF oscillation and also hum pickup. I got it sorted in the end, but the difference was that I had a good idea of how to sort it, unfortunately I think it would be a bit beyond you skills at the moment and would also spoil a very good 'classic' amplifier.