Welcome to the forum!
First things first...the Sunn specific section that you clicked on doesn't get as much Sunn traffic as the sub forum does. Here is the link for that: http://sunnforum.ampage.org/
All of the Sunn stuff was either identical to, or based on Dynaco hi-fi amps. The Mk3 and PAM preamp are the usual ones. The earliest Sunn stuff are Dynaco kits in a Sunn box, no joke! The later Sunn stuff once they had a single chassis instead of two chassis were slightly redesigned to be better for musical instrument use, but are still very similar to Dynaco stuff. There are many Sunn amps that are identical except for the name. So you may not find the proper schematic for your amp under one name but if you try another name, you may find that it is closer to what you have. The earlier amps used the EL34 and 7199 setup, and later ones used the 6550 or KT88 and 6AN8 setup. The later amps had higher voltages too. Almost all vintage amps have higher voltages today than when they were built as the AC line voltage is higher now than then. The result is that many of the Sunn amps will have higher B+ than what is shown on the schematic and some versions will exceed the max voltages for the electrolytic caps. Can caps are not as common today as they were when vintage Sunns were made, and are expensive when you find them. Using discrete caps inside the chassis with the Can cap still in place, but electrically disconnected is usually the best approach. It is cheaper for one thing, and the second advantage is that you can increase the voltage rating by connecting caps in series (with parallel resistors) and you can adjust the capacitance higher too. If you go this route make sure to solidly mount the caps to terminal strips. You may have to drill a hole to mount terminal strips. Also be sure if you intend to use a tube rectifier that you do not exceed the max allowable capacitance that those can work into. A GZ34 can support up to 60uF, though modern ones may not do as well there as vintage ones. Never use used electrolytics...its a false economy sort of like getting re-tread tires on your car. Just use new ones and that problem area will be fixed for a decade at least. One of the failure modes of electrolytic caps is that they can leak DC to the chassis, in which case your B+ would be lower than spec.
Never ground anything to power transformer bolts. It is an unsafe practice as vibration and heat can work those bolts loose, or someone down the road might replace the transformer and forget to attach the ground. The safety ground should always be attached to the chassis through its own bolt with a nylock or a keps nut, and left a little longer than the other AC line wires so that if the cord is pulled out the safety ground will be the last wire connected. This is code around the world. You may have to drill a hole in the chassis to add this connection. One of the quirks of vintage Sunns is that it has to be wired a specific way with the AC wiring in order to make the power switch light up. The correct way to wire up the AC section in a tube amp in the US is to have the hot wire go from the wall to a fuse and then a switch before connecting to the transformer. The neutral side of the line gets connected directly to the transformer, and the safety ground is grounded on its own bolt as mentioned previously. You can see a good example here (along with many other great tutorials) http://www.valvewizard.co.uk/standby.html.
Bias supplies are a negative supply, so the capacitors are reversed, with positive on an electrolytic connected to ground. Anything grounded to that cap's positive side should remain that way, however a heater center tap should be connected to chassis ground or to a positive voltage to float the heaters away from ground which reduces hum. The vintage way is to ground the heater center tap to chassis ground. Connecting it to a positive (or negative) voltage is a well known trick to reduce hum, but the positive direction is safer for the tubes ratings. Be sure that wire is in fact the heater center tap before you go moving it around. It might be ok where it is though as if it is connected to the positive side of the bias cap, that point is chassis ground.
I can't check the schematic and your pictures right now, but those voltages might be ok, or slightly low. The 7199 voltages are often all over the place so don't stress those as long as they pass signal well. Likewise on the pots, I don't recall what they used in Sunns, though I do remember they are different than the Fender usual regarding the linear/log thing. I also remember Conrad Sundholm (Sunn co-founder) telling me something about the pot choices (linear vs log) but I don't remember what he said as it was probably 10 years ago that we were talking about it. I'll have to see if I can remember what was said when I have a little time to look over the schematic.
What kind of undistorted power output is your amp putting out? Hopefully you have it connected to a resistive load and not a speaker, and have a True RMS meter to measure the power output? Knowing that will help us to know if the amp is functioning as it should or if it is down on power.