Jean Paul,
Over one year ago, I contacted Dr Lehnart to order one serie of knights; good relationship and shipping of the flats. But my laptop was contaminated by a liquidrop on the keyboard, and during transpotion of the data, my email files were lost/erased, so I can't recover the address. However I used the link from the web site.
I have seen Dr Lehnart published some painting of his wife recently on Facdebook, perhaps you can try to contact him through that channel. Another manner is to call him by telephone directly in Germany. he lives near Trier (Trèves) across the boder of Belgium/France/Luxembourg and he probably even speaks a few words of French !!! and surely English.
I continue searching in my files too....
Michel