I'd be interested in any info as well-I also have a Jean Van Maele boxlock 12g, 2 3/4 chambered and originally nitro proofed. Proof marks date it at some time between 1910 and 1923 if I remember correctly.

It's a very well used gun, most of the chequering has gone and someone has either painted or stove enamelled the barrels black some time in the fairly recent (last 10?) years.