Hi Rhys,
Yep, that one sounds definitely vintage! The Wall (are you sure it is a Wall? - there were other similar beasts) spanned WW1, so some actually fall into the veteran era.
When you say that you are missing the frame, I assume that you mean the cradle that holds the engine and wheel, rather than the bicycle frame to fit it to. These are hard to find.
We have the National Veteran Motorcycle Rally out here in South Australia later in September. We have a run for feeble veterans, and one enthusiast has threatened to bring his pair of his-and-hers Wall Auto Wheels!
Photos please.
Cheers
Leon