Birmingham Small Arms.
No sn data I know of
Here is the BSA link (below). I suggest you ask them directly.
"Best" is a relative term. Ultimately, it comes down to what works best for you. Personally, I'm fond of the BSA Martini .22 rifles.
BSA made several different air rifles. Unfortunately you did not state the model number and that is critical. You could try to contact BSA and ask them. see the link below.
To determine the date and manufacturer of a .303 British rifle, check the markings on the receiver and barrel. Most military rifles have manufacturer codes and year stamps, often located near the serial number. For example, British rifles might include the manufacturer's name (like Enfield or BSA) and a date in a four-digit format. Additionally, consulting references or databases on military firearms can provide more context on specific markings and their significance.
1919-1938. All BSA rifles produced between WWI and WWII were marked "STANDARD." They are all quite valuable if they are in Good to Excellent shape.
BSA actually stands for "Birmingham (UK) Small Arms" they first made guns; hence the 3 crossed rifles on the badge. Yamaha, who first made pianoes, copied the idea putting 3 crossed tuning forks on their badge.
BSA made 8 different Meteor model rifles starting with the MK1 to 6, MK 6 Carbine and a Super. Identify your model and state the condition of the rifle to get an estimate of value.
I am not sure exactly what you mean by "Full Power" so I assume you are asking about one that is NOT sold in the UK directly. The Mark 7 is the latest Meteor model. It comes in both .177 and .22 cal. It is made by BSA. (see the link below.) It is a Springer. BSA does make more powerful models in the PCP class of air rifles. The last reported price was around $300
This rifle must be rare, I can not find any information on it. I did find the following information on these BSA rifles in Mint condition. ( Yes it would be a collectible) Goldstar $450 Superstar $420-$480
The BSA National Council. They take thousands (if not millions) of recommendations for new badges a year, and occasionally create new ones. The most recent example would be Scuba Diving.
Birmingham Small Arms company. The early trademark was 3 crossed rifles. Birmingham, UK was fairly central to the British motorcycle industry.