Hi mate
No john didn't choke the barrel just did a target crown there was very little change in accuracy tbh
Yes I'd do a good diy strip and re lube as makes a big difference sounds daft but really does
You may find your spring has been clipped and not properly seated so you may want to do that too
As for twang mine really wasn't bad I did add a piston sleave but later removed as it was messing with the consistency
Properly lube the spring as that will dampen any twang I was properly impressed with mine
Little fiddly to strip with the little barrel blocks but a punch with a bend soon