CIA ruined a heck of a lot of CETME's, but I have found them that were not to buggered up.
Check the bolt-head, if there is any grinding on the back it will need a new bolt-head and locking block (and possibly new rollers) they ground the bolt-heads rather than change the locking block.
RUN AWAY FROM ALUMINUM RECEIVERS! They WILL crack eventually, they are not strong enough to handle the recoil.
Check head-space but running the cocking handle back and locking it, then slap it forward (Hollywood style) and drop the hammer to ensure full seating. The head-space is checked by measuring the gap between the bolt-head and the bolt-carrier. You cannot check the H/S with standard gauges, period, the H&K/CETME is the most forgiving of head-space of any rifle design.
Check the action by running the bolt back and forth slowly and feeling for any binding caused by improperly mounted cocking tube or barrel trunnion.
Check the sights either by actual bore-sighting (pull the bolt, mount the weapon securely in a vice and look down the barrel and the through the sights) or with a laser. Many CETME's have canted sights due to the above problems of improperly mounted front-sight rings. If you buy used and the front sight is torqued to one side, odds are the POA/POI is off.
Check the muzzle if it has a muzzle-break, CIA pinned them through a blind hole and often drilled too deep, denting the bore or even having the pin protrude into the bore.
The H&K/CETME is one of the finest action designs ever, yes it could use much better ergo's but these rifles will out run an AK! CIA's grinder-monkeys just made a mess of them. As far as reloading, yes, you will need to full-length resize the brass and the dent will reduce usable life on the cases but it can be done. H&K use to sell a buffer that attached to the reciever that kept the brass from getting dinged but I can't find them anywhere now. The CETME is better than the H&K both in respect to the trigger (assuming you have an original, CIA used H&K trigger packs in a lot of them) and the chamber flutes are different which reduces felt recoil. The H&K rear sight is better though, especially if you can lay hands on the PTR-91 fully adjustable rear sight.
Hope this helps.