The date of the Accident at Old Warden I have yet to discover.
I think the company that built the replica Alex commissioned shortly before his death and which is now in the RAF Museum is the same company which restored the actual aircraft after Desmond Penrose's forced landing.
If that is correct, they should know the date of the forced landing.
The company is called either AJD Engineering or Hawker Restorations - sister companies - and based in or near Ipswich.
You refer in your most recent post to 'John Penrose'.
I don't doubt John is one of his Christian names but he has always been known in the industry as Desmond Penrose.
Another snippet -
Forward visibility with the Cape config cockpit was very poor when the aircraft was on the ground. Henshaw taxiied it by walking beside the aircraft with his hand on the throttle!