Following the final crit I tried the font just as an outline font without the blocked in areas which I think is reasonably successful.
I went on to seek advice from Jo at this stage as I still was not completely happy with the final outcome. She had some useful suggestions and the actions from this discussion are noted on the actual sheet. The main point was to set some rules to apply across the font (where possible). This was something of a turning point as the work after this proved much stronger. The rules I came up with for the font were:
LEWIS FONT RULES
1. A blocked in area either the arms or counter, if two one blocked line, one thin line.
2. One wide block on the stemmed letters, if two stems then one block, one thin.
3. One thin line either cross bar,cross stroke
4. Exceptions the O is one blocked line.