This gold medal has the Stranraer town crest and the legend "ROYAL BURGH OF STRANRAER. INCORPORATED 1617" and "TUTISSIMA STATIO" (safest haven). It has a Birmingham hallmark and was made 1870-71.
The medal, bought at a car boot sale in Surrey, is a mystery. The date 1870-71 doesn't mark any particular event or anniversary. Perhaps it was specially made for one of the town's provosts.