Well efforts continue, I had intended to build a thickness sander, but after evaluating time and cost, I came up with a cheaper version, and since I intend to final thickness the ribs by hand this method worked just as well....
although a little research has turned up all manner of great tools that could take the ribs to final thickness....
here is an example http://www.byrnesmodelmachines.com/sander.html
Tool building is obviously an art in itself, another site of interest is http://woodtreks.com/
at this site there are several 10 min plus videos on how to tune a hand plane, mixing hide glue,
Japanese planes etc. well worth checking out.
I still intend to build a thickness sander, but since it started to rain this evening I got these ribs rough sanded just in time.
The final thickness for each rib is 1.6mm or roughly .062 of an inch, I was able to get the ribs between .080 and .120 of an inch or 2mm to 3.5mm something like that, I should be able to finish planing to thickness with a scraper.
I basically took a 3inch drum sander and mounted it in my drill press, then I took an old jack plane, removed the blade and used that as fence to sand the rib against, homely little set-up, but it worked.
Here are the pics, I did burn one rib, but I changed the sanding drum from 100grit to 80 grit and this took care of the problem.