Best left to a trained person.
I have a plainsman 175. I found the seltzer C02 10 gram bottles fit the BB gun. You can find then at most liquor stores that sell a seltzer dispenser's. sometimes they are called Creme chargers made by ISI. they come 10 in a box. ALSO WITH THE 175 put the C02 bottle in upside down. The piercing point is in the screw-on cap not up in the handle. I know it weird but the bottle goes in the handle upside down
Check the web under "Air gun repair"
The Bosch company has manufacturing plants across the world. The Bosch RN 175 hot air gun is currently made in the country of India due to the lower cost of manufacturing there.
The Winchester model 353 was made by Diana airgun for various air gun companies from the late 1960's to 1973. It's rated at 378 FPS with a rifled barrel. To get it repaired I suggest the link below. Locate a air gun repair shop near you and have them repair it. There are air gun repair shops all over the country who make a living repairing and modifying air guns and rifles.
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Most Sporting goods stores carry them. .177 will also fit your air gun.
I suggest you go online and do a search for "Air Gun repair" and select a shop where you can have it repaired. Or see the link below.
Depending on the model, There are shops around the country that repair air guns for a living. Do a search on the web for "Air gun Repair" and locate a shop near you to have it repaired.
See the link below for a list of air gun repair shops that maybe able to help you
A 22 caliber rifle is a firearm and a BB gun is an air gun (Not a firearm) Now if you are asking about a .22 caliber air gun then the difference is in the size of the projectile. A BB is a hard round .175 caliber ball. The .22 caliber is a larger size pellet.
There are many independent shops that repair older air rifles for a living. Do a web search for "air gun repair" and locate a shop near you to have it repaired or see the link below.