I'm really sorry to hear that Laurie.
I've asked it before, but are you 100 thousand percent, million-billion percent, sure that he's not in your overflow(s) ?? I can't tell you how many times I've been fooled myself by fish hiding in the overflows. The slightest bit of coraline and the lack of light makes for impeccable hiding/camoflage opportunities. You'd think, for example, that I would have noticed my trigger in there when he was in there ... no word of a lie I checked it *10* times and each time concluded "there is no fish in here" and then poof, that night I caught a glimpse of him when he allowed himself to be seen.
The flip side of the coin is I lost a sizable rabbitfish back in September and it was the same thing, just mysterious disappearance. I scoped and scoped and scoped my rock and finally caught a glimpse of something I hadn't seen before and could not identify. I had to take apart a good quarter of my rockwork to get at it and then I could identify it as a fish-shaped pile of goo that used to be the rabbitfish. I had seen him the night before so less than 24 hours and yet he was in a surprisingly fairly advanced state of decomposition.
No colour whatsoever .. totally blended into the rock and in a spot I would never have guessed a 6" fish could have fit into (either dead or alive).
Anyhow I'm very sorry for the loss if that is indeed the case.