Thanks Trevo. I used my trusty mm/inch calculator which translates the measurements to 44.88inches wide at the top, 13.74inches at the outside vertically and 11.02inches at the center measured vertically.
Hope it helps I didn't have an imperial tape our measurements Downunder have been metric for a very long time now but us older folk can still work in feet inches yards miles pounds etc a genuine sign of old age ��
I can't read either very well anymore, but your info helped very much. I have determined that the w/s frame I have is 35-36 open, not 33-34. The dimensions are spot on for 35-36 and the upper rail has a slight bow/curve to it. Thank you.