Polishing inside domes!

Has anyone attempted polishing a scratch on the inside of an acrylic dome? Is it possible? Are there low rpm electric tools which can help? Asking for a friend!! Really!

First of all, I do not have any experience with that. That said, I think that electrical tool should not be used. As discussed on the thread for polishing the dome, an electrical tool can easily take out more plastic than needed in a certain point of the dome.
Besides that, beeing on the internal face of the dome, the risk of that being noticed on photos is bigger. As the refractive index of water and acrilic are similar, on the external face is is not so problematic (even small scratches are not noticed if not taking photos towards the sun). But on the internal face the interface is acrilic-air, and so, everything will be much more visible (at least that’s what I think when considering the physics)

I have a novus plastic polish kit. Brand new $10usd plus shipping. It would fit in a envelope so shipping not to bad for price

It's certainly possible I would suggest as after all domes are internally polished when they are made, but doing at home is going to be difficult and I don't think it would be possible without taking the acrylic element off the port.  There is just not enough room to access the internal surface so you get the required even polishing.   Definitely no to electric polishing, too much chance of localised removal of material which means the dome is no longer spherical.

If the scratch is bad enough you might as well give it a go I would think or seeing as how you are disassembling the dome anyway see if you can source a replacement element.