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"
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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?