Manufacturer goofing on tank fitment is not good, but there is always a competition.
I was restoring my conversion about 10 years ago and original steel tanks sure were not repairable.
I found a manufacturer who had several shapes of tanks available and for the top fittings they had gaskets.
So when I bought the tank, I cut my own holes whenever I needed them and inserted pipes with "donut" gaskets.
Bottom drain has to be welded by manufacturer as the gaskets might not be reliable under pressure, but having space to play with, it was not a big deal and I don't remember paying $150 for shipping. Did they ship it from Hawaii, or was it 130 gallons tank?