I think there s some confusion over numbers of the complete glasses Ettinghausen and Grabar only suggest one for Minden not sure where you got the figure of two from I got one at Germanisches Nationalmuseum Nuremberg from but now I start looking more thoroughly I can t find it anywhere else Erdmann says there are two at Namur and other sources corroborate that Annoyingly I don t have access to Jstor so can t check the rest of the articles cited to see if they elaborate Also for the fragments where there is more than one fragment it s not made explicit what the minimum number of glasses represented by those fragments is as far as I can see 10 fragments doesn t necessarily 10 different glasses 81 147 148 65