Emailed the RAF museum but have had no reply
I think Malcom is right, the two bladed Watts propeller was only fitted to the first, pre war, Spits. It was quickly changed for a three bladed model. You have a very unusual item!
Thought i would raise this thread again as i sold this item i believe not long after this threadwas posted & i am trying too find the person who i sold it too . I can't remember if i sold it on here or on another forum (WAF) , so if the possible buyer if on here can contact me i would be most greatfull , or if you know the person who bought this can you also get them too contact me . Thanks in advance Mark