Asbestos is a very good thermal insulator, thus if you touch it it should reflect the heat of your hand back at you.
Thus, it should feel warm to the touch.
I can't see the exact details of the sheets, however, the CAWR requires that everything, & they mean everything is considered an ACM until proven otherwise.
If ACM's are suspected then the duty holder for the premises is under a statute law duty to get a suitable asbestos survey done.
Until then nothing is touched, else it is a criminal offence.
I suspect a refurbishment survey will be required. As far back as '74 it could be an ACM.
Not cheap, and probably not what you wanted to hear, but, CAWR is statute law.
Also as the Rev suggests in his own jovial way, Asbestos does kill, not instantly, but given the right set of circumstances etc. it does kill people.