Beretta 948
Hi. Take out the mag, put on the safety and lock the slide open. From the front of the bbl, push the bbl straight back toward the rear. You may have to "help" it with a mallet. Lift out the bbl from the rear through the top of the slide. Release the safety and just run the slide forward and off. You can do it!
No known sn data published
You will have to contact Beretta to find out.
check out Beretta's web site. Beretta has a chart showing the years of manufacture and the various symbols used. depending on the year of your 948, it could be shown as the 4 digit year as is mine. the symbol or year of manufacture is found on the left side of the frame in front of the trigger guard. mine was manufactured in 1952 and the full year is shown. Good luck.
Best to ask a gunsmith for help
You will have to call Beretta
80-250 USD
$200-$300, depending on condition.
50-400 depending on specifics
Around $200-$250, DEPENDING ON CONDITION.
Check the Beretta website.
Beretta Elite 2 has more power
Beretta 92F.