The MAUW (Dry) of a Kestrel 19 (Series 1,2,3) is 990 lbs... stated in the POH (Issue 2). Originally, it was 960 lbs dry, but Slingsby issued an update.

In the UK, there is a 3% increase (BGA concession, non-aerobatic) in dry weight to 1020 lbs, so there must be some engineering done somewhere at sometime to allow for that increase.

I would hazard a guess that going beyond those limits makes you a test pilot.

What you really want is a Series 4 Kestrel, which allows for an additional hundred pounds of dry weight!

-John Brake
Kestrel 19 #1789