I found another nice crisp b/w picture at a recent classic car exhibition ...showing 5R539 after its roof was cut and used in hardtop form at the SPA 1968 event. The only way for driver Claude Dubois to continue racing with his R-Shelby in his preferred class.
Note all the details - a nice task for the eagle-eyed researchers (wiper, electric cut-off button beneath the windshield, bumper openings, Le Mans rear flapper in the wheelhouse et...), because you'll find them on Mr. Dietrichs and Mr. Kienens hardtop later. Claude Dubois once said that he sold the car to his best memory to a german guy (Mr. Dietrich worked for Kleber).
Now look at this Stanford revslib picture and compare Mr. Dietrich/Kienens car at the 1970 DMV Rhein Cup Touring to the 1968 SPA 5R539.
https://cdm17257.contentdm.oclc.org/digital/custom/single-image?id=390316&collection=p17257coll1I also have the ONS race logbook of Mr. Kienens car showing that "5R539" was registered as a 1969 car in 1969 for them.