Carol, it was not uncommon for different types of MG cap badges to be worn by men in the same unit. And, I think this is an image of a group of fellows from the same MG battalion, perhaps even these are men for one MG section.
There have been several discussions about the grey tones and translating that to colours. It is known that earlier images used different chemical compositions and that could throw off a grey tone "translation". Please see this thread
http://www.britishbadgeforum.com/for...ad.php?t=58688. On the face of it, the patch appears to be either 3 Div or 1 Div.
The contributors to this thread have given you a lot of leads to pursue. Please let us know how you make out.