Hello
The following site link does not appear to have the Gladiator listed, but the WW2aircraft.net site is interesting, which has a number of Manuals under 'Technical', then select 'Other Mechanical Systems Tech.' for Forum members.
http://www.ww2aircraft.net/forum/index.php
They also share a link to a Russian site, which has a number of manuals, (not tried).
http://www.ww2aircraft.net/forum/technical/
Click the + symbol in a circle titled "Go to sub-forums"
I have downloaded a few Pilots Notes over the years FOC, although my Anti-Virus is kept updated.
Mark