Old fashioned rim lock keep!

Hi all, been stumped by fitting a rim lock for a customer replacing an old one.
The issue is I've fitted the lock but the keep sits to close to the frame for the latch to engage. I have to pad the keep out by about 5mm.

The door and frame when shut are flush, and there is no architrave round the frame so I can't pad out the keep without having to make good.
Is this how they make the keeps these days? I would have thought it would be common sense to make them fit as they used to?
I'll try to post a few pictures.

Top,
Don't remember any of my Rim Lock keeps being out as far as that.
Can you 'adjust' the keep by flattening (red) the roll of metal (blue) in the keep that the .... ///augh forgotten the name////.... ?latch? pushes against.


Or there is this which perhaps works better for flat/no architrave?
https://www.toolstation.com/shop/Ironmongery/d170/Locks/sd2611/Rim+Lock+with+Handles/p40083
SFK

Thanks for your reply SFK.
I tried rolling the keep metal but there isn't enough tolerance to allow the latch past the metal side even without the excess that is there!
I tried a dale rim lock from selco, the one I've pictured is Yale from b and q.
I checked the one from toolstation however both that they had in stock were tarnished on the handles and frankly looked cheap. Electro brass doesn't fill me with confidence either. Client wouldn't lime them I don't think.
I had a chat with my brother who is a retired chippy and he cant believe the issue either. Glad it's not just me, though I am the one pulling my hair out!

I fitted a chrome one recently and it didn't have the problem you describe. Almost sounds like they packed the wrong keep with the wrong lock!