Cr 18/4, A Cast Bronze Pig X 2 Coin, some help needed

First the question / help request -

An interesting, and a bit troubling, piece of information on the first coin below is the die axis. I looked at other examples of this coin series (Cr 18/1 - 6) on line. All but two of the examples I found have a die axis of 12. That is rotate the coin when holding it at 6 and 12 and the obverse and reverse are the same. My coin is one of the two with a die axis of 6. You can tell on most cast coins because they are not round, or are missing a piece. 
Should I worry about the coin being a fake?
Or, should I call it an almost unique example? (The other coin of this series with a 6 die axis was a pig / pig coin also.)

 

An interesting cast bronze quadrans arrived last week. It is from the second series of cast coins issued by Rome in about 270 BC. The weight basis for the series was the as equaled a Roman pound = 334 grams. The coins listed by Haeberline, 163 of them, averaged 84 grams => or an as of 336 grams. 
The vendor's description:
République romaine - Quadran (280-269 av. J.-C.)
A/ Cochon à droite trois globules en dessous. (ie - pig R, 3 dots below)
R/ Cochon à gauche trois globules en dessous. (ie - pig L, 3 dots below)
TTB (I agree it is VF)
Crawford - 18.4
Sear - 545 
TV - 11
Ae ; 69.36 gr ; 40 mm
I add the following references:
Sydenham AG - 46
Sydenham - 18, Note that the sale catalog of his collection listed 3 examples.
HNI - 282
RBW - 21
Haberline - pg 87 - 88; Table 36
Garrucci - Table XXXIV #4
SNG Cop 432 (this was listed on an old tag sent with the coin)


The Sextans & Uncia from the same series - 

Thanks to Red Spork for answering the following question - 
The old tag mentions C. BURGAN, 03-07-92, 530. This sounds like an auction from 1992. Can anyone scan the coin's description and pic from the '92 catalog?

With respect to C. Burgan, my library notes indicate that he was an auctioneer/dealer out of Paris whose published lists span the years 1978-2009 and include both fixed price lists and auctions and he likely had a retail operation as well. 3-7-92 likely refers to auction 30, held on July 3, 1992.