Insulation, Radiant and Vapor Barriers - hazzards of 1966 insulation bats

I'm remodelling my Minnesota 1966 rambler. I was just wondering about the building products used in 1966, specifically the insulation. I've ripped down the ceiling and walls in the kitchen due to excessive prior rodent activity (mice shredding the insulation and leaving behind tons of feces, fur and skeletal remains). Most of the dmage seems to be concentrated in the areas that were formerly ceiling lights, soffits and the adjacent wall cavities. I've removed all external wall insulation and a good amount of the ceiling bats from the kitchen. Should I remove any more from the ceiling if it is not damaged? What are the health concerns associated with insulation from this time era (1966)? I'm planning to put up a vapor barior before it gets sheetrocked either way, and I also plan to put in new roof vents, soffit vents, and more insulation (blown-in) later. Just wondering about the older stuff.
Thanks for any input/ advice

I dont think there are any concerns with old fiberglass insulation at least none that ive read about. If its not damaged/compressed shredded etc you could reuse it. I would though pull it down if you have already pulled lots. Then you would be able to get in there and make sure you air seal any places that could leak air. Then just add it back in there.