A small update:
The tank is in, and the seat is back in.
The tank certainly wasn't an exact fit, and suffered some small damage on a corner during shipping I think. But with some careful bending of the corner, some minor bending to hard lines to line up better with sending unit, I was able to find the bolt holes and get them all started while leaning in on the tank a good bit. I think everything should be fine. I also had to drill a hole in the top to mount the clip that holds my fuel and return lines, no big deal.
My gas cap doesn't fit this tank.
so I'll have to figure out a suitable replacement. Also no big deal, I'll take some measurements to the parts store and find one that works.
So here's where I am at:
New tank, new sending unit, new inline filter, new filter in carb, old lines (except new rubber at tank for sending unit). Same old carb that exhibited the flooding in the video I had up on youTube. I have a newly rebuilt carb at the ready. Oil change is needed due to potential fuel contamination from severely flooding carb.
Do I add gas and fire it up first with old carb and no oil change just to make sure I am back together properly, and check for leaks?
Do I try to see if the existing carb is fixable next, by taking the top off like some had suggested earlier? Or do I just skip that and put the new carb on?
Would it be correct to assume that I need to wait to do oil change until existing carb issues are rectified, or the new carb is installed? Or was the fuel due to the more severe flooding issues I had prior to now? And the existing carb not flooding "bad" enough to contaminate the oil.
I am going to open up the new one to check what gaskets it came with. If I mess with the existing carb would replacing the gasgets at the manifold pretty much be mandatory every time you remove it?
Thanks again all!