Well......... Close but not Cigar on Bastin..... More than likely, the tubeset does not slide but rotates as in the Système Colleye/Coleye/Coley. Thanks to Newcomer for putting us on the straight & narrow.



>>Maximilien Nicolas Colleye (also spelled Coleye and Coley; also traded as Colleye Fils) was a gunmaker/actioner located in Hoignée-Cheratte, Liège, in business from 1850-1865.<<


https://littlegun.be/arme%20belge/artisans%20identifies%20c/a%20coleye%20m%20n%20gb.htm

Serbus,

Raimey
rse