Deadpan - there is an annual memorial service for 31 SAS murdered by the Germans near Poitiers - it is around this time of year, but due east of us so unlikely to be that.
Sounds like to are referring to the guys from B Sqn 1 SAS who were murdered on 7 July 1944 following Op Bulbasket.
At that time there were no double digit SAS regiments/battalions.