Jay
I think Peter is trying to locate a Perspex bubble style screen, as most of us use, Mind you I could be wrong.
Simply remove windscreen from Ace and place Bubble style wind deflector on scuttle and secure with a series of cap head bolts into strategically placed Riv Nuts.
When refitting my Road going stock windscreen, simply put the Screen legs through the two slots in Scuttle reach inside the car and place pair of studs with hooked tangs through the frame and tighten the wing nuts by hand.
Usually takes eight to ten minutes if not distubed or not peeeeing down with rain.
Have a look at some period racing shots, or visit my Thread "Racing History of BEX333... 1957 to 1964 " there are a couple of pictures of BEX333 wearing a perspex bubble.
Bought mine Second Hand some 9 or 10 years ago.... Put a advert out in ACtion, some one must have one gathering dust from when they raced their Ace or Cobra.
Keith