What is this character?

[Mugi]

Just an interest in Chinese dialects and obscure characters. I do have quite a bit of reference material, but no time until the weekend to use it, hence I've only been able to give summaries of the characters I recognise (although the Kunming [口山] note did come from something I pulled from the Internet a couple of years ago, so I'm not sure how valid it is). Will try to fill in the gaps in a couple of days, although the last two characters in your list look as though they may be a little tricky to track down.

[Jack MacKelly]

cool, nice info

[Glenn]

About the 一 on top of 先 character, I've been told that it's an old character for 天.

[Mugi]

Glenn, you're spot on with the 一/先 character being a variant of 天. I discovered the same thing several days ago when I tried looking it up in the 汉语大字典. But because it still looked like a dialect character to me, I held off saying anything. Thought it might have had another usage, but as far as I can tell at the moment, it doesn't.

The 汉语大字典 also lists

[nipponman]

Thanks for the link Mugi, I love this kinda stuff.