Hello again Carling,
The 1910-11 vesta is certainly by J Gloster Ltd.
Can't be sure for the other two though. On the face of it Gloster continued to use the 1888 style punch but Ridgway & Priestley on the Chester marks identify J Gammage, later Lawson Ward & Gammage, having registered a very similar mark in 1900. Chester & Birmingham marks are very often identical. There's no published work on the Birmingham marks of course.
LW & G were a London outfit of manufacturing jewellers but vestas could easily have been on their product list so probably the best course would be to contact the Birmingham office @
http://www.theassayoffice.uk.com" onclick="window.open(this.href);return false; If you find something there would you please let the forum know.
Sorry I couldn't be more definite.
Regards,
Mike