I have seen three of four only, when I was undertaking insurance claim Surveys.
1/. as above Asbestos, left when parts of the air central heating was removed, one I saw had a vertical Asbestos shaft?
2/. External wall insulation as I recall was really thin or non-existent, a major up-grade may be requires to the insulation.
3/. Keep an eye open for any indications of rusting or rust run marks internally and externally, the outer surfaces were painted with a textured coating of some sort.
There is an entire estate sited to the East of Glasgow that I have been in, Insurance should not be to difficult it is an accepted design, and they are still standing.
Ken.