We bought our grandson's squirrel proof feeder at Walmart and it has a domed top. A number of squirrels have tried but none have succeeded and have to rely on the seeds that fell to the ground.
While my grandson has a "squirrel proof" bird feeder, the squirrels will eat the seed that's dropped on the ground below the feeder. So will the other birds, chipmunks, and rabbits too. Groannnn.
I've been using Detail Master or Model Car Garage seat belt hardware and masking tape painted for my seat belts/shoulder harnesses for a number of years and it seems to work well for me. What exactly are you looking for? Some of the older kits of the 60's had seat belts in them, however they didn't look that good.