Introduced by HMV around September/October 1929 the BR101J was one of the De-luxe 101 models, the brown being the third in line of brown machines following the Brown Crocodile and the Antique Brown which had a veining effect running throughout the covering.  

Coloured models had been introduced in 1927 with each model being given a colour code that carried on through both production of the 101 and the later 102.  Most of these codes were fairly obvious; LB light blue, R red, BR brown, BC brown crocodile but C for black and SB for blue crocodile defeat me.  No doubt is was due to problems caused simplification to initial letters and inevitable duplications.