The DPST Castelco's will sit side by side comfortable in a 1.1" hole spacing.
Neikeel may be able to help with the SPST Castelco's. If anyone in Britain wants to send some of these stateside, I would be happy to carry them.
While not period correct, you can also use the Carling type switches in the JTM 45/100:
A lot of folks use two of these SPST:
If you want to use DPST for the standby switch, I can also get these:
![Image](http://valvestorm.com/sites/default/files/imagecache/StorySize/CarlingDPSTToggle.jpg)