Mike,

The Laloux touch mark is more common than some think. It took a bit to make the connection, because many made the same assumption about it being a proof.

Here is the original thread from the Lefever forum about touch marks.
http://lefeverforum.informe.com/viewtopic.php?t=52&highlight=laloux

Observed touch marks on Lefevers:

ADH - Delvaux-Heuse, Belgium
GL - Georges Laloux, Belgium
LL - Leon Leclercq, Belgium
LLH - Laurent Lochet-Habran, Belgium
SB&Co Sanderson Bros. & Co., Sheffield, England
Three-lobed crown over a D, Didiere barrel works of St Etienne, France

Pete