Thanks Al.
No, just selective replacement of one for ten!!
I think I've found a solution...my wife is visiting the US in Oct; I'll get it delivered to her US office.
The Yahoo Group astronomical spectroscopy was set up to support and encourage amateurs in spectroscopy.
The Spectra-L200 Kit, a slit Littrow spectroscope was designed for the members, to give them access to a capable instrument at nominal cost.
Come over and visit...see what we do... http://tech.groups.yahoo.com/group/a..._spectroscopy/