Wet plate was UV and blue sensitive.

Tell your friend to set up the lenses for FdC lines and then it’s simply a focal shift for the UV & blue spectrum. Performance will be the same with slight scaling of aberration magnitudes due to the wavelength. This is what the photographers understood as adjusting from visual focus to “chemical focus” I think was the term.

Or, he can use constant transmission from 330nm up to where it begins rolling off at 425 and ending at 500. However, some modern glasstypes that would substitute for glasstypes that are no longer available won’t pass the lower UV wavelengths...hence working at FdC. Pass that on and he should understand.

(I’ve done the same exercise as your friend by updating the pre-1900 designs on dioptrique.info to modern prescriptions in Zemax).