Found today at the fleamarket, unfortunately heavily damaged to the base

Still displays nicely...
I cannot think of another maker than WMF Ikora, but the amethyst foot seems quite unusual.
Height 15 cm, hot-worked rim, ground base with circular polished pontil mark (so that does look very much like my other Ikora pieces). Lots of silverchloride in the upper part, which look almost opalescent against a darker background (see pics).
In the Ikora book there are two beakers of (almost) identical shape shown in the 1928 catalogue (PN 109), also shown in the 1929 catalogue on page 109.
Only problem is the size, which should be 13 cm; I don't know if 2 cm difference is an issue?
Am I barking up the wrong tree?
Thanks for any thoughts,
Michael