In article .com,
says...
Depends on age. Obsolescence may mean having to replace the whole
window.


Absolutely false.

With the handle in the "open" position it is simple to remove by
releasing two screws.

Whether the locking system is Cockspur or Espagnolette the OP will be
able to replace, the fittings are almost universal. A local fabricator
can probably supply from stock.

--
Ziggur

"S'ils te mordent, mords-les"