An expensive painting needs professional repairs by someone with professional training/certification. Given it isn’t an old master’s work of art, it may not be as expensive as one might think. If you decide to go this route, ask to see some of their repairs. If you end up with more damage than you are seeing now it would “devalue” your work of art.

Thank you, it appears that a small amount of inpainting would fix it, but I am hesitant to do that if it would decrease the value. I tried to remove it with a a q-tip with small amount of mineral spirits to no avail. I am also concerned about inpainting near crackling in the white.

Mineral spirits cannot dissolve dried oil paint. Be careful trying to do things by yourself, if you decide to move forward, read and practice first to avoid this:

https://www.youtube.com/watch?v=P8wCXeE-cD4

I think there are many situations in which a painting is worthy of preservation but not pricey enough to justify the cost of professional conservation. I like the idea of using a student’s services. But if such a student cannot be found, then I see no reason not to DIY, as long as you make sure that everything you do is reversible.

In the end, it’s a very personal choice. How much did you spend on the work? How much do you LIKE the work? What is your personal budget? What is your skill level? How willing are you to study the correct methods?

This page provides a pretty good place to start.

I would ask this question on the MITRA forum:
https://www.artcons.udel.edu/mitra/forums

I suspect it’s over painted minor damage that’s changed colour with time and now of course no longer matches the original paint. The damaged areas, probably scratches, would most likely been much smaller than the over paint. A practice that’s no longer recommended by restorers. If it’s been done with standard oil paint and been dried for some years, then it will be almost impossible for a non professional to remove without damaging the original paint, under and around it. Indeed even a professional will find it problematic.
The easiest thing to do would be to gently over paint, the over paint with a greener blue in watercolour paint or a restorers removable varnish paint. Try a dummy run first on a reproduction of the damaged blue area on another surface for better colour matching and paint handling when it comes to the actual thing. If you can’t manage the fake run, perhaps you should leave it up to someone else.