S&DJR Highbridge Works Erecting Shop c1903

It is hard to date this photograph accurately as no.15 was reboilered in 1905 & 1910, no. 46 in 1903 & no. 51 in 1903. No1 was converted back into a saddle tank in 1908.
(46 is ahead of 15 and 51 is beyond no.1 which is the nearest loco. This is what I have gleaned from using a magnifying glass on the original photo., but of course I could be mistaken. The cast brass numerals are viewed along the cabsides.)
14/8/2015 - I now notice that Colin Maggs, in 'Highbridge in its heyday' dates this as being pre-1895