this sounds fascinating. I bet I would like the look of it. As for a possible finish:
flax oil, heated to near smoking point. I put this on an earthen floor I made in the garage. It was practice before I put it in an upstairs bedroom.(never did the upstairs thing).
For the garage floor, I bought gallons of flax oil (from soapers choice dot com), and heated it and applied it very hot. I did not want the "boiled linseed oil" product they
sell at the
local big box hardware store because it seems to have VOC type thinners in it, no longer is simple boiled linseed oil.
I found instructions somewhere and
should have used several coats but only used the one, and it penetrated deeper in some places than others, definitely not the "ideal" the prescribed application. Even so, the finish was very durable and hard and resistant to water unless- the water was left pooled on top of it, which would be handy if you wanted to remove it, or repair or change it.
Very important to note it "off gassed" for quite some time, and I've heard others have noticed this. If I were going to use it in my living space I would plan to do it early in the spring and leave the windows open all summer and late into the fall.