Well it's back together and 'Speccy' is showing mid 40s with a fairly quiet fan.
Yes, a lad that set out to do this job on Youtubby did remove the keyboard, but I was able to see all I needed from the bottom. A multi vane outlet had to be poked out (with soft copper wire) above and below the heat conductor rails, thus doubling the tedious task. I had no means of blowing but vac'd on the fan side while puffing into it or poking. The strange thing is how much was just inside those vanes given that I'd vac'd it in Texas. It just did not pull the dust through. I think there is a good chance that carpet of dust did move away during the flight, and flopped back as described. However, I'm braced for a sudden change and a hurried build of my Texas PC should this occur.
Average temp is reported as 45 - 48, so not as cool as I'd hoped. I'll have to put some work in to see if I can control that speed a little as described earlier.
I'll look at your link for future reference. I'd like to keep this and make it my PC replacement. My smaller Vaio is fine for lugging. Thanks again. Fingers crossed for now.