I have a similar camera to the K1000, a Ricoh KR-5, and although I have never used it while it was raining, it has been SOAKED twice, and I DO mean soaked !! Once it was dropped into a river while I was fishing, and another time it was in a garbage bag in the bottom of a boat , and I found out the bag had a significant leak , when I took the camera out of the bag water was literally streaming out of it. And it STILL works. Although the film that was in it was ruined by the water. So if your main concern is if a little rain will hurt the camera, I doubt it. I wouldn't go out in a monsoon though The good thing about these all manual cameras is there are no electronics on them except the light meter. So a little water is usually harmless to them.
the k-1000 is not waterproof or weather tight as in the pro bodies are with seals, or-rings and such. Don't be afraid to use your d70 out in the rain. Keep it under your jacket (a poncho works well for this) until you want to compose and take your image. Keep a dry microfibre cloth to wipe any water drops of your lens front element and your good to go. When your done wipe down your camera body with a soft dry cloth and then go play with your images. Lots of people have produced stunning images on rainy wet days with all sorts of cameras. Post some of the one's you like best so that we can all enjoy.