Canada - Northumberland Militia Officer's Victorian Silvered Large Pattern Button converted to lapel badge

A very scarce silver plated Victorian large pattern button, circa 24mm in diameter, close-backed, maker marked, but due to a crude application of a shaped slider with solder, it is hard to make out who. It looks like it could have been Jennens & Co. Most of the plate has been rubbed off. I have checked with those in the know and indirectly had it confirmed via Howard Ripley that it is not English but Canadian Militia. Never seen another one. So condition aside, it is considered scarce. If the buyer would like the solder slider removed, I can arrange for this.