@Oilyrag? Help required!

Another old family Box Brownie photograph scanned.

I know where the picture was taken - behind our local CO OP store visited late in the afternoon - sitting on what I think was called Well Lane (will amend if Mum tells me otherwise). Above the wall in the background was a row of small brick terraced houses called Well Row. Mum was born and grew up on Well Row. The lady in the photo is her Grandmother who lived in a similar house just out of frame to the left. I think the baby girl is my Auntie Hazel who still lives local. The motorcyclist is unknown to us, a family friend maybe.

And then there's the motorcycle, a mystery that may never be solved but if anyone knows please chip in! Am putting my bets on a Norton Model 20 from the late 1930s given that there is an exhaust downpipe on the nearside, but am hoping @Oilyrag will either confirm or correct me on that *fingers crossed* 

First Edit: Mum thinks the baby girl is herself, not Auntie Hazel. She isn't sure about the motorcycle though ;-D