Hi TH44,
Nice gun!

I think the name on the rib is actually Jean Van Maele. (not Malle)

You could try googling "Jean Van Maele rifle" or similar.
Like Kuduae said, that could be the retailers name rather than the makers.
The rifle looks like it is very well made, along the lines of Francotte or other quality Belgian makers.
As you say, the inletting is very well done.
It looks like it has had a tidy up done recently, and the lumps appear to have had a clean up on their lower surface for some reason.
But I say again, it appears to be very well made and is a very nice piece.
Hopefully Capt Curl and others here will have a close look at your photos and give their thoughts on the rifle.

Also, Kuduae's advice on doing a chamber cast is spot on.

Are their any other marks/stamps on the barrels or action?