Any pointers on finding a manufacturer who produces medium scale heavy (like .128) strings?
 

You might check the D'Addarios... we have to buy their extra long scale strings to fit regular long scale Alembics when customers have requested them. Perhaps their long scale strings will fit a medium scale Alembic... it's worth checking into.
 
If I ask LaBella really nice like, they will make small quantities of special strings. They like to get orders of at least 25 sets for this service, and it sure ain't cheap, but I'm not aware of a whole lot of ther options.