Firstly. That 'style' of g is quite interesting. Why? Well it's not Zodiac's typical lower case g. Zodiac's most often used is this.
Then we have variations on those. Here are a few examples. They are obviously Zodiacs g's but look at the differences. They are quite varied once you get into detail regarding head shapes etc.
So this brings us to the '78 letter. What's so interesting about the g's. Well for one thing they aren't Zodiac's typical g's. In fact they aren't even that similar to any of the variations (in the accepted letters). They are however closer in style to the g's used in the Citizen letter. That's kinda interesting though because if you were a forger would you pick and use exclusively a style of g that was only ever employed in a Zodiac letter that technically isn't even a Zodiac letter?
So I compared the two sets of g's out of curiosity and in doing so I noted a similarity in the variation range in the tails on the g's. The tops are obviously different but the ones in the citizen letter share striking resemblances to other ones used by Zodiac. It's the tails he varied but what he appears to have done is carried over the 'variation range ' in the tail shapes.
Here's what's confusing me. If you are trying to fake a Zodiac letter why would you create what is technically a new style of g albeit with previously used habits in the tails only? Ok, lets say you spotted that trait in Zodiac's own letters and are attempting to recreate. If you are going to that level of detail why can't you create a letter that looks authentic in all aspects. Why does this letter look like a forgery yet contains, at least to my eye, some very clever subtleties.
There's more. That style of g, I thought had only turned up in the Citizen letter but it technically hadn't. It had already made an appearance in the Belli letter. Again variation on the head but similarities in the tail variations. So what the? lol. Is this a really convoluted fake or is it something else. Anywho, my eyes and brain need a rest so here's some more pictures to hopefully illustrate what I'm on about. I'm not sure I know anymore.


