Perplexing Prussian Pattern coins

This 1740 Kingdom of Prussia silver pattern coin is listed as KM Pn7

N#266122

And here's the corresponding gold ducat, listed as KM M3

N#266121

My 3rd edition of KM 1702-1800 list one 1740 pattern, Pn7

And it shows it corresponding to M4

I can't find and “M” coins in the Prussian section of my KM.

And then there's this coin also a 1740 Prussian pattern with no KM number in Numista

N#355770

Here's the corresponding ducat

N#199401

My questions are: Does anybody understand the “M” numbers in the Prussian section of KM? Are the Pn7 and M3 coins listed correctly? And are there KM numbers for the other pattern and corresponding ducat. Maybe this is all cleared up in a more recent edition of KM?

thanks, Michael

Same in the 7th Edition.

M3 is a reference number.

ok, so the reference to “KM# M3” in this listing is incorrect?

N#266121

And this one is not KM# Pn7, because that's a pattern of M4

N#266122

I guess I need to try and find 

Martin Klaus, Die preußischen Münzprägungen von 1701 - 1786

The other references to Olding FrII# 374 use the same number for the Ducat and the Pattern

thanks 

Unless you know what M3 and M4 are I don't think you can know which is wrong.  My SCWC does not reference any M3 under Prussia.

I agree. What I'm starting to realize is that these pattern coins are not well documented in general.

Eventually I'd like to nail down which pattern is the real Pn7. 

And if 

N#266121

is really M3 from Martin Klaus, Die preußischen Münzprägungen von 1701 - 1786

we should list it as that, not “KM# M3”

That book is pretty cheap in Germany, but $50 shipping to the USA

It's at a few university libraries in the USA, but none near me.