Mr. Robert B. Marvin put out a small pamphlet/booklet in 1972 titled "The Identification and Analysis of Luger Proof Marks".
I believe. Mr. Marvin is still alive and may live in Florida.
On page 69 he writes : "..This Luger DOES exist. It is authentic, though it IS also mis-understood. We believe that the Spandau was produced for use at the Spandau prison, and made up, mostly, from parts secured from other sources. There are other theories on this too, however...".
On pages 34 and 36 he does show photos of Spandau toggles with and without the crown/k stamping...and goes on to state that all the Spandau lugers shown in his booklet appeared to have their stampings stamped and not engraved.
I am not sure how Mr. Marvin's theory held up to date...
Regards,
Pete... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />