Yours may not be doing a very good job. You can purchase them from any of the usual suspect vendors or you can make your own. If you choose to make your own please know they'll cost less, you won't have to pay shipping fees and they'll probably seal better.
Assuming you chose door number 2, please go to your local auto parts store and purchase a bit more than 4 feet of 1/4" vacuum hose. O'Reilly's is not known for being the least expensive and it was $1.20 a foot there. Maybe 50 inches or so. Cut 25 inches of it and using a fresh single edge razor blade carefully slit through only one side of the vacuum hose keeping your cut as close to a straight line as possible. On mine there were numbers in white every 6 inches or so and I just aimed to cut on one side of them. Take your time doing this. Now slip it over the lip of the headlight ring as you see I've done in the first image below and replace your 4 clips. Please note the one at the top is diametrically opposed to the bottom mounting screw hole. The top clip is made so that it matches a slot in your headlight mounting piece. The two clips on each side are the same and the bottom one is slightly different. Images of those below.
When you replace your headlight ring you may need to put some Armor-All on it or maybe some dish soap. It will fit tightly now so you won't get any water nor dirt in there. Hope it helps.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
