Emperor Maximilian's Cipher from 1496?

I uploaded a new article, "An Imperial Cipher from 1496?".

This is about a cipher recently identified independently by Daniel Bourdeau and George Lasry. Lasry dated it to 1496, to which Bourdeau concurs. If this is indeed from 1496, this may be related to the beginning of use of symbol ciphers by the Habsburgs.

My article concludes with two desiderata. First, crucial evidence of the dating seems to be G. A. Pecci (1755), but I could not see the correspondence. Secondly, if the cipher is shared with Sienese, the Habsburgs may have learned the cipher from them. I wonder whether the letter is really addressed to Sienese envoys.

If someone can find out anything, I'd like to know.