Now is the time to source and fit some new blades for your mower (if you haven't done it already !) whilst time is on your side.
Just to confirm(or perhaps explain slightly better) the sequence of gears on any ferguson 35,135,165,, etc etc.starting with lowest ratio to highest ratio is 1L, 2L, 3L, 1H, 2H, 3H (this isn't necessarily the case on other makes of tractor where the ranges sometimes overlap)
So if you run out of power in 1H the next gear down is 3L.
Don't hesitate to ask any other questions you have. Great to see the pics of your kit in action.