Hi there! I have a very nice Olympus OM-1 MD camera that will make an excellent astro camera.
Camera is in excellent condition, with a few caveats. The mirror has some wear in a few spots as shown in the picture; I can send you a larger image if you'd like to check it out more closely. Viewfinder image doesn't seem to suffer noticeably though, so no functional impact. Also, the film advance lever doesn't spring back into place after shutter release. This is only an issue for fast snapping anyways and will be of no consequence for astrophotographic or normal daytime use. Otherwise, camera and included 50mm 1:1.8 Zuiko lens are in excellent condition! Camera comes with body cap and front and read lens caps.