5-valve broadcast model.
There are two versions that look very similar, but one has a reversed dial (low frequency on right instead of left).
The Collier & Beale version was also sold as the Pacemaker 519P
This name was used on a few different radios over the years, physically they bear little resemblence to each other although they are all 5-valve broadcast band mantle radios.
The radios in this series are:
Intermediate Frequency: 455kc/s
Frequency Bands: 1
Chassis Notes(most schematics can be clicked to download a full size version)
At least 2 chassis variants - one of which has Philips(?) style IF cans, a miniature valve in the lineup, a different tuning cap (and reversed dial) and other differences like the orientation of the tone switch - probably one set built for HMV by Philips NZ while the other (main version) is Collier & Beale. Both sighted models have 'Manufactured by H.M.V. (NZ) Ltd'.
Service information (HMV_495BC_Little_Nipper_-_5V_BC_AC_-_1949.pdf) here
General Construction Notes for Collier & Beale Ltd:
Model numbering followed no real sensible scheme until around 1940 - and prior to 1934 apparently no model numbers were assigned at all.
From 1940 a 3- or 4-digit system was employed where the first digit indicates the number of valves, the second digit is the number of bands and the third is the year of manufacture. From 1950 the last digit became two digits, eg: 5151 is a 5-valve broadcast-band only from 1951.
From 1957 model numbers were replaced with model names, ie the Pacemaker Buffalo - which makes the year of manufacture hard to determine unless service info is consulted (although C&B often released service info after the radio, and the date on the service info was for its release, not that of the model.