Thanks all for your suggestions. I think I am going to go for the 110 with the full realisation that once I get to use it I may then find it best to sell the 107 and get a 87 or similar.
My rationale is
a) The 122 definitely fills an important slot in my quiver and that may be because of the specific conditions that seem to crop up regularly in the main spot I sail. The 110 is the closest I can get to being a similar board but up to date.
b) My 107 is a great board but I often use the 122 in preference in lighter winds....and experience so far has been that when the wind is much stronger I could be more comfortable on a smaller board.........so maybe the 87 is a better option.
c) No way I would ever not have the 127. In the less dense summer breezes this board is an absolute dream and also good for more long distance trips.
The new 110 is only 4 litres less than my 122, the same width, and a more modern overall design. So it sounds the right board.
In the shorter term having both 107 for rougher water and 110 for somewhat lighter wind and flatter water, is probably a bit of a luxury but you only live once ...right?