Homebrew PCBs

Hi all, I am new to this group and come recomended by the AMATEUR 
REPAIRS group. I am in Australia and have a question. Can anyone help 
me with the instructions for using 8007 reversal film. I have used it 
a lot in the past but either my memory has failed me or the film I 
have left or the developer have gone off. I can find no information 
on the net at all. If it is the developer gone off is there any thing 
else that will do the job. I have a quantity of negative acting 
circuit board I wish to use and do not like the TTS system. Any other 
Ideas would be most welcome as I only have 1 sheet of 8007 left.
many thanks ,
Don VK3YV.