The Brits Sgt Spontoon finial is the basic design pattern... main reason I asked confirmation on the length.... This specific type of finial was also popularly found used with regimental flank markers during the CW era... but these were smaller on a short single piece tapered staff..... Occasionally a larger version of same found used on some flag staffs.. before, during and post CW era... Since this is a two piece staff with only friction joint it is most likely post war era... and intended for use as a static display on a stand.... not field use... which are normally found as a solid one piece staff. The British Spontoon's finial were usually made of Iron/Steel since they were intended as an actual weapon..
Here is one with the same finial pattern used on a early war flank marker
Similar pattern finial used on a Pa regimental flag staff