Glad you got it all sorted, sound like a nice rig now.
All the non factory parts on that ad scared me away.
On the " If it was a great gun, they would be keeping it ' I simply disagree esp. on the 7 different National championship rigs I have seen sold, they all just wanted something new. Sure the lefthand TX sat for a number of years between taking the nationals and being sold, as did the P70 and ... .
On the modern cheap master blaster firearm replacement model from unknown airgunners that are third hand and 6 mo old, might be good to shy away - unless face to face which is always best- . Personally well over 100 used airgun purchases and only one with hidden issues ( okay a couple did have an extra mark or two but did function correctly. Get out there and meet a hundred or two airgunners and just buy from people they know and folks who know them, many a grand deal to be had. And, high Quality ( as in excellent quality control ) need no warranty , just be sure they havent been tinkered with and save the money.
John