Here is the report of Dr. D. Johnson regarding the comparison of the surface analysis of PT/35(b) and a Thuring board DP/347(a). (The spectra will be uploaded later.)
DRJ218: Page 1
The conclusion is simply devastating for the case against Megrahi, and indeed Libya.
PT/35(b) simply does NOT come from a Thuring board. End of that story.
Reference
The DJR218 Report (6 March 1992)
PT35B 