Thanks Grandarog - It looks like it`s the Foresters Arms, corner of Oliver Street and Henry Street, listed as 82 Henry Street on the dead pubs site.
The 1901 census goes from Oliver Street, only a short road - another relative was living there at 18 then - straight into Henry Street at number 38 where there is a beer seller - but it gives no other detail. 82 also shows as a beerhouse, kept by an Alfred Randall which is the right surname from the dead pubs site.
It seems quite likely that Filmer would be there, the family had a woodyard opposite the Elephant & Castle pub at the bottom of Castle Road, 152 Luton Road, and he and his wife ran a greengrocers at 168 on the corner of Leonard Road. So just round the corner - but I have yet to find Oliver Street on any maps.