Hello Redman, i've this contact of Mr Tetzel:
Magdeburger Zinnfiguren, Heinz-Dieter Tetzel, Wespenstieg 2 39120 Magdeburg. Telefon: (03 91) 6 21 25 99
Unfortunatly no more infos. If you have some positive success, please report to me :-)
Here some funny annotations from Rick Sandred's webpage (about Muller-Erfurt engravings): "Magdeburger Zinnfiguren – no link - Heinz Dieter Tetzel, Wespenstieg 2, 39120 Magdeburg, Germany – Tournament ca. 1450 with jousting knights, spectators, civilians celebrating, courtly nobles, artisans and armorers (see Ortmann, pp. 101-105 for examples), but this vendor is generally unwilling to sell to anyone he doesn’t already know! "
Claudio