The SR-1 was launched in 1959. It’s possible that your copy could be 61 years old! Even if it was stored in an airtight box, oils and greases will break down over that time and become tacky.

Add actual use, dirt and dust, and that tacky can become gritty. The result is that functions begin sticking and then eventually freeze.

Most people will buy one of these old cameras and use it until it breaks, then toss it and find another. However, if you cherish it, then have a pro clean, lube, and adjust it - usually a couple hundred bucks. If all the parts are good, a clean and relube will get it going for decades more.

If you are mechanically inclined and want to give this a try, then try to find the service manual. I didn’t have any luck for the SR-1 but did find this one: http://mattsclassiccameras.com/wp-content/uploads/2016/07/Minolta_SRT_Service_manual.pdf

Obviously, there will be differences but there should also be some similarities to help get you started. The inside of a mechanical camera is more like a watch - don’t use a camera as your first foray into fixing devices...unless you are very much okay with breaking it.