is it bad to frequently swap prisms in a pentax 67?

I was looking to get a spare body to go along with my pentax 67ii. seems they have gone up in price over the last year or 2. anyway, I was looking for a regular 67 with an un-metered prism and use the 67ii to meter or get a separate spot meter. KEH seems to have a 67ii body with no prism for a good price. is it harmful to use one prism and swap it between the bodies? or do i even need the prism at all? I shoot 85% landscapes on a heavy tri-pod (but can use the 645 handheld successfully).

I plan to have one loaded with 100 iso B&W and the other with either 400 speed B&W or with velvia 50 rather than one 67 and a pentax 645n as the backup

thanks

I can't speak for the 67II. Is the prism compatible between the 67II and the older version of camera? One consideration with the older version cameras, if you remove the prism then you will want to remove the lens also to properly align the chain. I haven't damaged my camera yet. But, on several occasions I thought I had. If it were me, I'd purchase the required prisms.

http://www.cameramanuals.org/pentax_pdf/pentax_6x7_pentaprism.pdf