Awesome responses! Big thanks! I think together we figured this mystery out.
The body really looks like the RG470FMTK in the picture in this catalog page.
The color in person really depends on the light cast on the guitar. In daylight it looks more black. Inside, sometimes it looks purple and sometimes it looks more like the color of rootbeer. That's kind of cool that the colors vary so much according to the casting light. This is why I think it is the TK color rather than the TP color. The color chart from the '94 catalog confirms that.
I never even thought that it could have been the RG470FMTK because of the maple fretboard in the catalog pic.
Another part of the mystery solved, the extra (fifth) hole in the 550 neck heel doesn't look factory drilled.
That and the flat part of the heel sticks out a bit makes me think that the neck is a replacement neck for the original maple fretboard neck.
If it really is originally a RG470FMTK, then this guitar had several big mods.
1) From original neck to the rosewood 550 #2
2) From original Lo TRS to Edge bridge
3) From original pickups to DiMarzios
I think she's a keeper. Pretty with some pretty cool mods.
I'm about to send her to my luthier for a setup and to install a Sustainer 401 pickup kit into her. Talk about a modded guitar now...yep, she's a mut, but she's mine.
Big thanks to all here who helped me figure this RG out.