I've got 30-odd hours invested in a model, and I simply cannot comprehend MOI well enough to get it completed. I'm looking for assistance, either paid or unpaid - your choice.

What I'm trying to model is fairly straightforward, and MOI has all the necessary function, but I just can't make it work. Attached is a picture of an earlier version, as 3D printed in stainless/bronze.

Bottom line: want to make a quick $100 via PayPal paid in advance?
Work with me on this model so I can finally get my product out the door (many months late).

It's not a complex object: a truncated cone, curved to 45-degrees along its center axis, and capped with a hemispherical end.
Total height = 50mm. The base diameter is 20mm, the upper diameter is 27.5mm, and the dome size the same, with no "edge" between dome and cone (blended or fileted together where they meet).
The base should be solid for the first 15mm of height, and the rest of the interior hollow, with a consistent wall thickness of 3mm (and no inverted triangles on the inside that cause sliders to make it solid). It needs a concentric roughly 9mm stepped-diameter hole from the base into the inside, where I melt in a brass insert.

And I need it locked, so I can't continue to screw it up every time I look at it it... I'm so frustrated with this it's making me nuts, and I'll happily pay to get this part Done.

Anyone want to get involved? I'm certain it's no more than an hour or two for anyone who knows how to use MOI well.