Can anyone please help?

I have White (aluminium) double glazing. It was installed by the previous
owner about 15 years ago.
It's in basically good condition apart from the hinges which have been
progressively failing over the years.

These are the hinges for the top 'lights'.

I have replaced many myself by drilling out and re-riveting in place. The
company I bought the hinges from have now closed and I've run out of my
supply stock.

I saw some on screwfix but it's almost impossible to tell which are my type
from the description given.

Refer to http://www.screwfix.com/app/sfd/cat/...03922&id=15620 for a
good example of what I'm after. The dimension given doesn't seem to match
any I can find on the existing hinges. i.e. pitch between fixings for
example.

So is there anywhere I can buy some over the counter? I don't want to order
10 pairs (say) and then find they are wrong.

I live in Essex if you know of a local source or maybe a good company I can
order from will do.

Many thanks in advance.....

Regards

Paul Hodges