I sold mine some time ago to Gunnerman. One copy is listed on the website. Possibly, for a fee, they could scan the date code page for you
http://www.gunnermanbooks.com/?CLSN_4893=1476827628489331bdc9e8aef4197f46&keyword=Trade+%26+Hallmarks+on+Firearms+in+Belgium+&searchby=title&page=shop%2Fbrowse&fsb=1&Search=Search