Poland 1923 2 Grosze - but in Bronze - not Brass?

I have a 2 Grosze 1923 from Poland that looks to all the world to be a bronze piece and not as it is supposed to be - brass. It is not listed in SCWC, but I have found a polish forum discussing it's existence here: http://forum.tpzn.pl/index.php?topic=3545.0

And a for sale listing in Polish translated in image below:

Can anyone verify that the cataloge reference below is real: Parchimowicz P104A. - and that the coin/pattern should exist?

As can be seen from my pictures, the 2 grosze look to the naked eye fully bronze. It is much darker to the naked eye than in the pictures, so I added a 5 groszy that is known brass variant as a comparison. 

Should I have it analyzed for metal composition?




 

It's possible it has just worn/weathered to a darker patina.  For example:  https://wcn.pl/archive/327767?q=2+grosze+1923+

But if you know someone who can do the analysis (XRF?) sure!

Sure. It can be natural. Although the example you point to, the 1923 is clearly brass and the others bronze. My 23 looks bronze

The coin is going in to be certified/slabbed after conferring with a auction company/coin shop.  

Crossing fingers and toes.