I see you are well into the potential mechanics - very interesting. I have been interested in the possible interpretation of certain symbols in the 4 by 17 symbol sequence. There are interpretations based on various well-known symbols in traditional numerical an alphabetic systems in standard use in the medieval period. And going beyond appearance, there is also a physical, positional confirmation of the visual appearance for three different interpretations of the fifth symbol in the sequence.
VMs symbols 2 and 5 appear similar to the medieval numbers '4' and '7' - and have the same distance between.
VMs symbols 1 and 5 appear similar to Greek letters 'omicron' and 'lambda' - and have the same distance between.
VMs symbol 5 has the form of a Roman numeral 'V' inverted - and it is in the fifth place in the sequence.
Interpretation is one thing, but placement, positional confirmation, needs to be built into the sequence intentionally.
VMs symbols 2 and 5 appear similar to the medieval numbers '4' and '7' - and have the same distance between.
VMs symbols 1 and 5 appear similar to Greek letters 'omicron' and 'lambda' - and have the same distance between.
VMs symbol 5 has the form of a Roman numeral 'V' inverted - and it is in the fifth place in the sequence.
Interpretation is one thing, but placement, positional confirmation, needs to be built into the sequence intentionally.

