Good plan! It looks like there's another eBayer out there who is equally suspicious of the Holmegaard provenance.
Saying that, it has been known for Aseda to pick up Holmegaard designs (the Aseda dog-bone/jack-in-the-pulpit vases which scatter eBay and carboots (and my parents' living room), for example, were originally a Lutken design).
One thing that makes me suspect the signature, aside from the design, is the fact that the seller can read Lutken's 'LP' monogram, but makes no sign in their auction or question response that they know who Lutken is. The Lutken monograms I'm familiar with look nothing like 'LP' to the untrained eye.