Sorry to rant here but sometimes I see online what I would consider a "Dynaco abortion". This is (what appears to be) a stock Dynaco ST-70 with an older GSI driver board. Now there is nothing wrong with removing the stereo/mono switch or maybe even drilling new holes for your input jacks but ....
1. If you are going to do a complete rebuild at least repaint the transformers.
2. If you are going to put in new tube sockets, at least have them all match. The one's on the front are the stock black tube sockets and the sockets on the chassis top are brown colored and are "top mount" rather than bottom mount like the front sockets.
3. Don't have "resistor stacks" visible on the driver board top. If you want to use them place them on the bottom of the driver board. Hey - did you notice that the two bias adjusting pots on the sides of the driver board don't even match?
4. Look at that "upgraded power supply" with wires and resistors hanging all over the place. If you are going to do this you probably could have squeezed them in INSIDE the amp. Yes - they were put in circular capacitor holders but there are no bolts holding the capacitors in place! If he ever shipped that amp, the UPS gorillas would probably see to it that those caps would most likely fall out of their circular holders.
Sorry to rant, but it really pi$$es me off to see someone do this to an ST-70.