Might be the right tank, but with wrong decal.
The magneto doesn't even look like its Evinrude. Looks more like Johnson to me.
All model 310's would have been equipped with battery ignition from the factory. Model 311 would be electric-start. The 310 should have a cast iron flywheel with the typical Elto aluminum starter knob on it.
The tiller handle you have is correct, its the short version. There is a longer tiller handle that was also available. no spacers per se, just one friction washer (part # 170114)
I have a service manual with parts list that I can scan, but I'm busy for the next few days, so won't get to it until Monday most likely.
Don't worry too much about the timing, you just have to position the pistons at TDC and set the cam so the points are just starting to move, and you should be in the ballpark at least. But would be better if you either acquire the original flywheel and timer, or else convert it to an Evinrude magneto, but at the moment I can't exactly say which Evinrude magneto you'd even be looking for. Probably one for a Speeditwin would work, depending on your crankshaft taper. I bet what has happened is that somebody cut the hub out of one flywheel and grafted it to a different make altogether.
Hope this helps eh