I have a friends corgi brockhouse for sale, it was a runner a couple of years ago and was stripped down for restoration and never touched since. He thinks its all there but has moved a couple of times since. Open to offers. Pictures available on request. Email me on lazarus152 at hotmail.com
I'm no expert, but the unusual nature of the bike led me to Google.
As far as I can make out, the WW2 bikes were Welbikes. Brockhouse produced a derivative from 1947 onwards. The first Mark of these was exported to Canada, bearing the name Indian Papoose, Brockhouse having bought out the US Indian motorcycle manufacturer. This looks more like your photo. The Mark II was sold in Britain under the name Brockhouse Corgi from 1948.
It could be worthwhile checking on it's history before advertising it.