Thank you guys, Answered all my questions. I have the rear 90 degree corners so can complete rear.  Will take your advice and install front and just try and source 120 degree corners to finish off.
  . Thanks again.

Hi guys, just a follow up.
   I installed the front and rear windscreens back in my car on the weekend. All went well. It took about 1.5 hrs for each (that's rubber and all chrome inserts). It went better then I thought it would. (rear chrome insert a lot harder then front) All parts from Rare Spares. Can get the chrome corners from the UK and will install them when I get them.
  cheers.