Carse Antiques has dated this piece to the 1910s.
The plane is of dovetailed steel construction with the old-style gunmetal lever cap with the markings as can be seen in the photos (which is rare in itself).

The front knob is ebony with an insert brass collar for the securing screw. It is noted in the Nigel Lampert book on Spiers that a number of these very early Spiers planes of this design had an ebony front knob which is totally original. The rear fully enclosed handle is rosewood with a matching insert brass collar for the securing screw, the handle is in perfect condition with no cracks and full spur. We believe the over-stuffed infill around the original rear handle is probably a later addition.

The plane comes with a Mathieson backing iron and an almost full-length thick parallel iron by Arron Hildick, we believe both to be original as the fit is so snug and the mouth so tight. As can be seen, the plane has seen very little action during its life. The size is 13 3/4" long by 2 7/8" wide with a 2 1/2" wide blade. Having been dealing in tools for well over 30 years now I can say with complete confidence I have never seen this exact model before, I have had similar ones but not this exact one, RARE !!!!
CIRCA; 1910 - 1915
Carse Antiques has dated this piece to the 1910s.
You can view the stock and full dealer information on the Carse Antiques Profile Page
Carse Antiques is a registered member of LAPADA