Thanks!! Well my first question is...
My grandad's name was original written as Frederick Abel, Abel being his father's surname. The Abel is crossed out and Kavaney is written above which is his and his mother's surname. I thought for a start this was a simple mistake however there is 2 National Insurance numbers written on the form, the first being scrubbed out but still legible if you shine light through the cloth paper its written on.
Any ideas on what this might be about? a simple mistake or perhaps he used his dad's surname informally before he joined the Marines?