by mhole » 20 Feb 2017 18:28
The Ingersoll site you linked to is nothing to do with the manufacturer, just a Locksmith who capitalise on the name.
The L blanks haven't been made for years, and the market is so small that none of the aftermarket blank manufacturers are interested. A couple of years ago I came across an E keyway, no blanks available, despite having been used on a 20+ apartments in a purpose built residential block. IIRC I also encountered an R (or maybe it was L like yours?)keyway, long since discontinued and unsupported, I think it was originally a US military keyway, god only knows how it ended up on a private front door in the UK.