No. The Hamburg firm of M. Kimmelstiel & Co acted as a dealer and distributor, not as a subsidiary or sub-brand of Montblanc. The correct name of the pens is Der Kimmelstiel, and it is documented in the specialist literature. Listings that present such pens as a Montblanc sub-brand rest on a misreading of the imprint.
The dates tell against the attribution as well: the pens carry a patent notice from 1903 and thus date from before the later Montblanc was founded in 1908 (then the Simplo Filler Pen Co.). They were made by Moore, a manufacturer that had already been in business for several years. The early Montblanc pens accordingly took their lead from this filling system, and not the other way round.