An authorized repair center might have what you want.
The Fast Deer is a Chinese made Air-rifle. It's model KL-B3. If you want more information go to the attached link at the bottom of this page.
Yes it can but getting the current rifle "Tuned" by an expert will get you better results. Tuning will make the spring and trigger perform better.
It all depends on the condition of the air rifle. Without more information it is not possible to answer you.
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
A reverse tuning slide allows the air to flow smoother through the tuning slide area of the trumpet. In most trumpets, the top end of the tuning slide fits into the leadpipe creating a small obstruction where the air meets the rim of the tuning slide (inside the leadpipe). On a reverse tuning slide, however, the tuning slide fits over the leadpipe, eliminating that obstruction and allowing the air (in theory) to flow smoother.
In radios that aren't solid state, and use variable capacitors for tuning, the air-dielectric variable capacitor is the almost universal choice for radio frequency applications. More information on air variable capacitors is available at www.orenelliottproducts.com.
It hard to find information about this line of air guns but I know they were made by "GAMO." I found a magazine add for a new one on the web that was dated 1972
You will have to take it apart. Each model is different so you will have to find a diagram of the rifle.
Hot air balloning
Are you sure it's not a Benjamin air rifle. I know of "NO Jefferson air rifle company", But Benjamin air rifles have been around a long time. If so what is it you want to know.
You can find information about automobile air conditioning at any auto store. You can also go online and search under air conditioning to find the information about automobile air conditioning.
The only information that I could find is that Kral AV Industrial makes the Demon air rifle along with several others. The company is in Turkey, and has made air rifles along with real rifles.See the link below.