The first evangelical revival took place in Barvas in 1822 (not free church), followed by revivals in 1902, 1908, 1910,1922 and 1939. All these would have been in the Free Church. The 1939 revival was probably even stronger than the 1949.
For more information see, ‘Glory in the Glen,’ by Tom Lennie, p265, 292-3, 369-385, 463, and ‘Sounds from Heaven, by Colin and Mary Peckham (for details of the 1949-52 revival), both published by Christian Focus Publications.