Can you use patch 3.41--3.42 on v.3.38?

I'd rather like to see continuous and concurrent patches otherwise.
makes it easier to store the original offline installer only, and patches.
Instead of several installers AND patches.

No, because you can't upgrade from 3.38 to 3.40. That patch is missing.
If you want to play a 3.4+ version, you need to download a new installer.

Does this mean I have to reinstall the whole game... to get to 3.42 ?

unfortunately, yes.

perfect, thanks for the info!

the link does not work for me. I only get page not available.