Symbolism

One of the may interesting gravestones at St Bridget's Kirk.

This appears to be the grave or tomb of a senior stone mason. The Master Mason would be accorded this privilege. Gabriel is watching over; there are compass at the base of the panel and a carving tool on the right. 
The left hand tool is one of many types of chisel. The "wreath" at top centre is likely to be the moon which was often used in Masonic symbolism to represent the Virgin Mary. 


Many thanks to Bootneck for the above information.