I'm surprised they won't fit standard cranks but then again Lambert did make their own chainsets so perhaps they used a non industry standard thread. The pedals look to be in super condition so it's a pity they won't fit.
If I find out any more I'll post back.
EDIT - are you putting them in the correct cranks? Right and left threading remember.
I've just checked Velobase and they say the crank thread is standard -
http://velobase.com/ViewSingleComponent ... 5&AbsPos=0
Today is the yesterday of tomorrow.