Thank you guys very much for chiming in. I'm relieved that the Celtic Cross has a great root system! I'm used to phals and vandas, so I was unimpressed when I pulled it out of the pot.
The Celtic Cross came to me in some kind of medium-coarse bark mixture, but the bark was breaking apart when I took it out of the pot. I've got it repotted in a generic medium bark mixture with about 30% sphagnum moss to try and retain moisture. It's now in a clear pot so I can see the moisture levels.
Thank you, PaphMadMan for your insight. I had no idea what to expect with these plants, and very much value your experience as a "paph mad man"
I'm certain that water got on the Celtic Cross' leaves during the summer, so hopefully that is the explanation for the leaf dimples. Also, thank you for confirming that the multi-floral is seedling-sized. I did pot the two seedlings up together, also in a bark / sphag mixture.
I'll do my best to be patient and hopefully they will hang in there until Spring.
Incidentally, I read from the Baker culture sheet that some of the paphs they were caring for needed a winter dry period. Should I be providing drier conditions for either of these plants?