I am looking for the same grips as you, let me know if you find a source.
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The Wards Western Field model 5 is the same as the (Sears) JC Higgins model 85, both of which are the MAPF (La Manufacture d'Armes des Pyrénées Françaises, later Manufacture des Pyrénées - Hendaye) Unique model D2, also known as Le Corsair, which entered production in the mid-1950s. The model D came in varying barrel lengths and were named D1 through D6, depending on barrel length. Unique went out of business about 2005.
Parts can be obtained from Numrich and Bob's Gun Shop , and replacement grips specifically from Vintage Gun Grips . And, of course, parts show up on the usual firearms auction sites, Gunbroker and Auction Arms, and sometimes on eBay (there are no firearms on eBay, but gun parts are sold on it).
Check under all three names -- sellers do not always list all available parts under all the names.
25-50 USD or so
To have a purchase on the rim of the ammuntion.
Any auto shop such as Auto Zone will have headlight replacement bulbs. Also general stores such as Sears or Kmart offers replacement bulbs in their auto sections.
Ask a gunsmith for help
One can purchase replacement Buick parts from many retailers. Replacement parts can be purchased from Buick, from auto parts retailers, and from other people via the internet.
One can purchase a heater core replacement from a number of online retailers. They are available to buy from eBay, Auto Parts Warehouse, AutoZone and JC Whitney.
One can purchase replacement parts for a Chevrolet Monte Carlo car at 1A Auto. This site offers a parts type list for one to find the replacement part needed.
The first production semi auto pistol was the Mauser c/96 "broomhandle" pistol.
The cheapest place to purchase replacement auto parts would be from a junk yard. You get a better price since you usually have to pull the part yourself. If that is not the route you want to take there are several website where you can purchase discounted parts.
There are a few different replacement parts that can be purchased from Autozone Auto Parts. One can purchase new windshield wipers, new engines repair kits, and a tire jack there.
.45 ACP means auto cartridge pistol ( I believe they spelled it pistole though). The .45 auto just means it is an autoloading pistol unlike the revolver style pistol.
A Buick Century License Plate Bulb replacement can be done at home. You can go to any auto store to purchase the replacement part. Replacement can also be done at dealerships if needed.