Today I finally replaced the dividers that were too small and fell out when I moved the records. Some of the letters had dropped off too.
Avoiding over-priced plastic product, I did it myself.
I wrapped old LP records ($2 for 25, op shop) in sturdy brown paper (free, re-use shop) and stencilled letters (50c, op shop) with a marker pen ($4, discount stationer).
Smart, cheap, effective organisation.