well thats about 47 inches,,
so maybe the draw on the bow was about 23 to 24 inches,,( maybe shorter, there are guys here that will no more about yew)
if it was sinew backed maybe a bit more,,
I am not an expert on yew,,
most good bow wood will make a heavy bow at short draw lengths,,
I am guessing 70 to 100 depending on the width of the stave,,