I recently purchased a used Gen4 Glock 19 from another GT member. The transaction was an absolute mess, however I can't say I think the seller did anything intentionally to complicate things. Details and drama of the transaction aside, I wanted to run a few points of this pistol by those more familiar with Glock pistols than myself to see if there is anything I need to be concerned about: - Date of manufacturer is July 2010. Pistol was unfired (no marks on barrel whatsoever). I cleaned it and lubed it appropriately, it was extremely dry when I received it. Has RSA marked 0-3. Glock has the 0-4-3 RSA in the mail on its way to me. - Ejector is marked "336" (I believe those were the numbers), I ordered a new Glock trigger housing for a Gen4 9mm from Lone Wolf with the Glock tool to replace the ejector with the new one, marked 30274. - The seller installed Meprolight Tru-Dot night sights. According to him, this was the only modification to the pistol. Upon receipt and after further inspection, it also appears to have a smooth trigger, most likely from a G17? I can't find anything that might lead me to believe any Gen4 G19s ever shipped with smooth triggers... So I'm guessing that at some point someone swapped this trigger out. - When removing the slide (confirm unloaded, pull trigger, pull slide back 1/4", pull down take down levers), the slide slides forward off of the frame about 1/2" to 1". Then it stops and appears stuck. Pulling the trigger again lets it slide right off the frame. Is this typical for Gen4s? My Gen3 G23 slide comes right off without having to pull the tigger a second time. -This is the more important one in my eyes:. In the grip cavity behind the magwell, there should be a few ridges which from what I can tell help secure the backstraps on the Gen4s. At some point, someone ground off the ridges smooth. The grinding/filing marks inside this cavity are actually quite clean, it doesn't really look like a hack job. I'm guessing someone used a dremel tool for this because of a few scratch marks on the adjacent wall directly inbetween the magwell and this cavity. The cavity now resembles that of a Gen3, and in fact, the grip plug from my Gen3 Glock 23 fits in this Gen4 perfectly now. Was curious if, besides the "surprises" with the transaction, anyone sees any red flags as far as using this pistol for training and CCW purposes? My intent was to keep this absolutely stock aside from the night sights and shoot the crap out of it at the range.With the FTE and BTF issues the early Gen4 19's had, I think the RSA and ejector updates are rightfully called for. I dont know if the removal of the ridges pose any structural concerns of the frame now? Thanks for any help or insight.