I Understand what your'e saying but I think the plastic is very strong on the original and i was believing they were a common item, obviously not.
I have got someone to repair the dome with fibreglass and plastic glue, its looking good so far.
if anybody does know of these items let me...
Hi Harry. I know its been 3 years since the subject was mentioned but did you ever find a replacement dome. I have exactly the same problem. and need to purchase the same dome you had?
hope its ok.
Tony