8 inch F/15 project

I am considering working on a mothballed 8" F/15 project this winter. The lens was amature ground and I am guessing it is a crown flint combo. I have yet to look at any sky object through the lens, but does anyone have any idea how the final image should look like. Color diagrams or spot diagrams?, or say a 8"f/15 doublet would be comparable to an 8" F/6/8/10 of what other lens design?

Heres a spot plot. Blue is on the left, green in the
middle, red on the right. The black circle is the Airy
disk size. It will be somewhat blurry in the red and blue.
This assumes normal C-F color correction.

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Here is a popular 6inch F/8 achro for comparison.
So looks like your 8inch F/15 will be somewhat better
in terms of color correction.

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Heres a simple ED doublet 8 inch F8 for comparison...

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And just for fun, a fancy ED doublet
8 inch F/8....

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