Raimey,
I do not know if there was any relationship between Cap and Falla. I do know that I have one of Falla's trademarks mistakenly attributed to CAP on my web page. Something I have to fix.
Without a patent number, who can tell?
I did pull the following information. Unfortunately Francotte patents were never registered here or in Germany that I can find. Online access to many early Belgium patents is non-existent. Francotte did register some patents in England. While not as complete as the US online patents are, the British online patents are better than most.
Charles Francotte
1 New or Improved Safety Device for Fire-arms with Pivotted Breech-blocks. GB190704736 Published 1907-04-25
2 Improvements in Martini-Francotte Rifles GB190611093 Published 1906-09-06
3* Improvement in Bolt Rifles. GB190611092 Published 1906-08-09
4 An Improvement in "Martini-Francotte" Firearms. GB190216583 Published 1902-09-11
5 A New or Improved Breech-block for "Martini" Firearms. GB190216582 Published 1902-08-28
6 Improvements in Breech-loading Small-arms. GB189800596 Published 1898-03-19
7 Improvements in Breech-loading Small-arms. GB189800251 Published 1898-02-26
8 Improvements in Cartridge and Cartridge-case Extractors for Breech-loading Fire-arms. GB189800076 Published 1898-02-05
9 Improvements in Repeating Pistols. GB189713345 Published 1897-08-21
Auguste Francotte
1* Improvement in Bolt Rifles. GB190611092 Published 1906-08-09
2 Improved Indicator for Breech Loading Firearms. GB189710082 Published 1897-09-18
3 Improvements in Single Trigger Mechanism for Double-barrelled Fire-arms. GB189709897 Published 1897-08-21
* Auguste and Charles shared this patent.
Pete