Looks like we're both new to the forum! Luckily I've owned and prattled with plenty of roller delays.
Congratulations on the new CETME! I've just purchased a CETME L in 5.56 myself.
As far as the trigger goes... yup.
The Spanish CETME C's never boasted a great trigger and are crunchier than a potato chip.
I highly recommend you do NOT send your trigger for work. There are only so many people that I trust to work on HK/CETME Triggers as far as machining and it's frankly more economical to purchase a new trigger pack.
Here is an exceptional trigger: https://www.hkparts.net/shop/pc/PTR-...-550p17014.htm
Note! Because you are using a CETME pattern, this pack will also require a German pattern 3 position (SEF) housing, and a German pattern selector.
Sadly, this pack will not host an ambi selector.
On to muzzle breaks. I have a limited working relationship with JP and boy do they have great devices. Do yourself a favor and get a brake, not a flash hider.
DO NOT USE A LINEAR COMPENSATOR. You may over-gas and these are only adding to the recoil and wear of your roller delay, particularly on your locking piece. Linear comps are more for shorter gas operated rifles like AR pistols and SBRs which have the ability to bleed excess gas more generously.
And please, familiarize yourself with the trigger group. The entire pack can be removed from the housing as if it were made of Lego. Go through the manual for your CETME. DO NOT disassemble this pack once it is out! You only need to occasionally remove the pack from the housing to oil lightly.
All the best.