Derek Cohen (in Perth, Australia)
Steve, further to the excellent comments from Wiley, I use Veritas PM-V11 Stanley replacement blades in my LNs (#3 and #4 1/2). The blades, as you are aware, are thinner than the original LN, although slightly thicker than Stanley. They work very well in the LN's: close up the mouth slightly via the frog, and use a closed chipbreaker (where a wider mouth size does not matter anyway).
Regards from Perth