Plaster question (long & complicated)

I’m currently painting my parlor ceiling (first time since we moved in over 10 years ago – yeah, we’re slobs) and I’ve got a few questions regarding the decorative plaster.

Firstly, what’s the “official” name for the kind of wreath in the corner of the ceiling shown in the picture? Is it called a medallion, like the decorative item that typically appears in the center of the ceiling, or does it have another name? For the purposes of my subsequent questions, I’ll just call it a “wreath”.

One of the wreaths had some cracks across it and I could push it in its center and feel that it had separated from the substrate. The same situation had occurred on one of the non-decorative areas of the ceiling and I had taken down what proved to be a skim coat over the basic plaster ceiling in that area and re-applied a new skim coat. I couldn’t adopt such a cavalier attitude in the case of the wreath, however, for fear of the whole decorative emblem falling down. I cut out a square in the center of it and discovered that, while still comprising basically a skim coat over the plaster, it had some kind of fiber mixed in with it (horse hair?). I figured that one way to attach it back to the substrate was to cut a series of sections out of it, in the flat areas, work some vinyl spackle into the gap between the skim coat and the plaster substrate at the edges of the sections I cut out, and wedge up the entire wreath to the substrate until the spackle set and hardened and, hopefully adhered the wreath to the plaster again. Of course, the actual decorative portions of the wreath are still not actually stuck to the plaster, but I figure the bonding in the remaining areas, together with the fiber that seems to make the wreath more or less monolithic, will keep it up there. With just a couple more sections to cut out and adhere, it seems to be working pretty well. Am I on the right track with this method, or should I have done what I thought might be an alternative, namely cutting out the entire wreath at its edges, hoping it all stayed in one piece, and re-adhere it in-toto?

So, then I come to the back half of the parlor and find that I have a similar situation with another of the wreaths, except, this time, rather that a couple of distinct cracks in the skim coat, the entire flat portion in the center is sort of “crackled”. This similar to what portions of the cove at the perimeter of the room looked like and I was very pleasantly surprised to see that, when I painted these areas of cove, it was like the paint was penetrating the surface and actually in and of itself adhering the skim coat to the plaster substrate. Essentially the “crackling” virtually disappeared. Is this feasible and, if so, would it be likely to have the same effect in the area of the second wreath, thus saving me the painstaking “cut out / pin back with spackle” routine?

Last question (I promise). One of the eight wreaths has been bodged (yeah, English word for which I know no US equivalent – look it up) beyond repair by previous owners. Has anyone used one of those artisans who reproduce and duplicate existing plaster details and, if so, could you offer recommendations and maybe some idea of what the cost was?

Sorry to be so long-winded, and thanks for any replies (except vitriolic ones!)