Hi, As far as I know the name has always been MARR but I have only traced back to late 1700s. James and Martha MARR arrived in Australia about 1850. and the family settled in country Victoria around Talbot and Mildura.
James' brothers and sisters stayed in Scotland, the 2 sisters didn't marry and nor did I of his brothers, so there was only 2 children from another brother that carried on the Marr name from that MARR family.
But there must be some missing siblings as I cannot believe in that era that James MARRs parents would have a 10 year gap between children.
The rest of the MARR clan here have many descendants in Australia and all have kept the MARR name..
My mum is the MARR family descendant.
Her DNA is on the 23andme site.