Thanks for that shanew147......
However, I suspect FindMyPast show records from the
Courts as distinct from the
Prisons.
The records I'm looking for relate to persons sentenced by the Military Courts during the War of Independence - I don't think FindMyPast show such records.
I'm reluctant to signup to yet another site such as Familysearch - even though they seem to have the record I want

Does anyone here have any experience of /thoughts on Familysearch?
Regards,
SuasAnAbhainn.