We've had loanees going back to the turn of the century, so no, but to my knowledge, he was our first loan of what could be considered the "modern era", as incoming loans became a regular thing after his spell.
Inside forward, better known for his time with Charlton Athletic and Portsmouth, has died aged 82. He made 11 appearances and scored two goals for Bees on loan from Portsmouth during the 1967-68 Fourth Division season...
Taken from an unsourced wiki entry, which states that David Harney, a forward who made one appearance during the 1969/70 Fourth Division season, has died aged 72 in Kent. He played most of his league football at Grimsby Town and Scunthorpe United.
An attacking player for Bees in the 1961-62 and 1962-63 seasons, he has died in Victoria, Australia at the age of 81.
Percy Gleeson, who was one of the oldest-living Bees still alive, died in Barnsley in October 2015, aged 94. Born on 18 July 1921 in Acton, he scored one goal in 9 appearances at inside forward in 1947.
Scottish winger who made 232 appearances and scored 22 goals between 1958 and 1964. He passed away in Luton on 5 September, aged 83.