Hi Dylan, thanks for starting this thread as it's a topic close to my heart. I visited the Cappy Froissy Dompierre last June so maybe I can give you an update?
#1257 ALCO 2-6-T 57148/16 (exTPT) has gone to Tacot Les Lacs.
The CFD website lists BLW 50HP 0-4-0 tractors 49192 & 49966 of 1917 but the one in the CFD museum carries a BLW worksplate #48606/18 - see photo below.

Tacot Les Lacs has an extensive (and growing) collection of WW1 equipment http://tacotdeslacs.free.fr/collection.html
Apart from the well travelled #5104 BLW 2-6-2T 46828/17 they now also have ALCO #1257 from the CFD I'm sure that I read that they had acquired a BLW 4-6-0T which had been converted to diesel but I'm darned if I can remember where I read it!
Tacot have another 60cm g. BLW tractor apart from #7001. There is at least one other (6 according to one report) which has/have been converted to standard gauge.
Hope this helps.
Ray.