I recommend you go online and do a web search for "Air gun repair" and locate a shop that repairs your model, or see the following link.
http://www.airgunarena.com/index.php/Repairs/Parts
Yes, the Spitfire was an excellent fighter.
lets start with. Who made the rifle? there are over 100 different companies who have made air rifles.
Blue Book of airguns says "typically between $150-$200 price range."
You can still order 1077 parts from Crosman in New York. See the parts and owners manuals link below. Then contact Crosman Customer service and order your parts.
Crosman still has parts for this rifle. contact Crosman at the link below (Customer service) and order the parts you need.
The Crosman 140 Air Rifle was made from 1954 to 1968 in four different variations. Crosman no longer makes parts for the rifle but you can still get it repaired. The Crosman home page offers a "Find a repair center" button on their first page. From there you can locate a center that has parts for your rifle. See the related link.
Crosman does. see the link below for the parts list and how to contact Crosman.
Crosman owns both the Benjamin and Sheridan line of air guns. See the link below for the Marauder parts list and the customer contact page for Crosman ( They sell parts for the PCP rifle.)
Many Air Forces used the Spitfire. Principally, the Royal Air Force, but also the US, Canadian, Australian, New Zealand, Russian, South African, Belgian, Dutch, Norwegian, French, Portuguese, Greek, Turkish, Israeli, Egyptian and Indian Air Forces.Ref - 'Spitfire, the story of a famous fighter' -Bruce Robertson.'Spitfire, a complete fighting history' - Alfred price.
Go to airsplat and you should find what your looking for. Or you could look up "air gun repair" on the web.
Crosman still supports this model and has parts. See the links below.
Daisy air rifle and Crosman air guns made air rifles for Sears under the Higgins name. Any Air rifle that starts with 799 was made by Daisy air rifle. Any air rifle that starts with 126 was made by Crosman. To get them repaired I suggest that you go on-line and search "Air Gun Repair." There are several places around the USA that repairs and reseals old air guns.