Leupold is one.
Burris Brand Scopes make scopes for various uses. They make binocular scopes, rifle scopes, spotting scopes and tactical scopes. It is the only US based optical scopes company that has kept all production in America.
There are lots of companies to make rifle scopes with well design and proper zoom options. Nikon scopes are classified as the greatest in looking optics.
There are Several Excellent air rifle scopes, but keep in mind that many of them can cost much more than your rifle. Here are the names of just a few. Bushnell, Hawke, Leapers, Centerpoint and Gamo. All of these makers have a wide range of scopes at different cost. I suggest that you go to the link I've posted below and make a choice.
You can see the google for step by step process, few of the branded organization they make rifle scopes just likenikon as you can see different more organization branded item in saffordsportinggoods.
Simmons makes two type of scopes. They make a rifle scope. This attaches to the top of one's rifle. They enable the shooter to see his/her target clearly. They also make a spotting scopes. It is basically a scope that sits on a tripod for use in the field or shooting range.
Some scopes can cost more than the Air Rifle. Leapers makes some excellent scopes for around $250. Whatever scope you purchase make sure it is designed for air rifles. Air rifles, because of their forward / reverse kick, can break a regular hunting scope not designed for this type of rifle.
I am a little confused by your question. Do you mean Webley air rifle. I know that Wembly makes scopes but I am unaware that they make air rifles. If you mean Webley then I need to know the condition and the model of the rifle to give an estimate of value.
They make a number of different models. Why not ask them directly about the model you have in mind? 1-989-705-8885 is their phone number. E-mail : support@muelleroptics.com
Marlin did not make scopes. They had their name put on scopes made by someone else.
Yes http://redfield.com/
A 4 x 12 x 40 works great. Just make sure you can adjust the parallax down to 10 meters (or less) and that the scope is air rifle rated. The recoil of some air rifles will destroy non rated scopes.
Zero-magnification optics (meaning, they do not make the target look closer) such as the Aimpoint, EOtech, etc... are not telescopic sights. However, rifle scopes (which ARE magnified) that have "red dot" or illuminated reticles, are indeed telescopic.