mp4 to avi/mpeg conversion
Apologies I'd being faffing with different scaling settings and must have got my files mixed up. The following (quoted in the question) does in fact work on this product - Living Images Li1210.

ffmpeg -i in.mp4 -vcodec mpeg4 -vf scale=480x234 out.avi


However the following scaling seemed to produce better results when converting from 1280x720 (youtube standard download)

ffmpeg -i in.mp4 -vcodec mpeg4 -vf scale=416x234 out.avi


And I think this addition from this question produced a slight improvement

ffmpeg -i in.mp4 -q:v 6 -vcodec mpeg4 -vf scale=416x234 out.avi