The best place to find them would be online stores. Websites like eBay, TheClockSmiths, BcknTime, and ProClocks would all be good places to find authentic antique clock parts.
An antique grandfather clock will most likely turn up in the first antique store you visit. Although if there's no antique store in your neighborhood, you will also be able to find them online (where u might also want to use terms like Longcase Clock and Floor Clock).
Real antique trunks are harder to find these days after a surge in interest in them in the late 1970s into the 1980s. Authentic antique trunks are found in antique shops, generally. This site offers the real thing: www.eagletrunks.com/ You can also find reproductions as well. Check out www.woodchests.com
Find a good antique clock dealer in your area. He or she can refer you to a person who know how to repair or can do it for you.
You can find parts for your Ford tractor at www.TractorHouse.com
Parts for an antique radio can be purchased at such places as Ebay and Old Radio Parts. Other places where they can be purchased would be Golden Antique Radio Services and Phil's Old Radios.
One can find parts for antique tractors at chop shops that sell used vehicle parts. In addition, one can search at used car lots for cheap parts for tractors as well, although they might not have tractor parts.
At Antique Clocks Priceguide, there are resources there to help you find how much the grandfather clock is worth. Besides pictures to browse through, there are appraisers that you can contact.
There is many places to fix an antique mantle clock. The best would be to find a local clock repair that knows their stuff. If there is not an clock repair close to your area, you can always turn to the internet. After a quick search on google, you will find Dr.Time's clock repair, or a little further down you will find a guide to how you can fix it yourself. Always turn to google when looking for answers about an unknown subject.
There are a number of places where one might be able to find antique kitchen cabinet pulls. These include Historic House Parts and House of Antique Hardware.
Brass Bradley alarm clock made in Germany
You could try going to a pawn shop. They are everywhere, and there are many different items to choose from. You can also search for antique jewelry in local newspaper ads or anything else of the sort.
A collector can find an authentic American Civil War sword on eBay or on websites like "Civil War Antiques Shop", "Antique Guns" and "Michael Simens Shop".