Hey, G'day..., I like living in Western Australia, been here 10 years and glad you like it!
As you know the hydraulic fluid tank is not pressurised, otherwise you would not get away buy simply pushing it in before work, it would pop out! As I said, all it needs is a good de-grease and glue in, may be a good time to replace the fluid as you lost a fair bit of it anyway and repair the sight glass when empty. I think high quality silicone may do the job but for a few extra $ you can choose one that won't react with the fluid, all should be readily available from your local hardware store.
As for the size of the tractor, I'm happy with what I can do with this, sometimes would need a bigger one but most of the time it is manageable, overloading it will give you an indication of it's limits, sometimes trying to lift heavy things..., the thing is just unbreakable for what I need and if overloaded, it just simply won't do but didn't break anything just yet. The FEL has a capacity of 500kg so anything over will lift the tractor before breaking any parts. The capacity is always tested to much higher loads in case of this.
I love my 273, Ferrari red, great design compared to the green's & oranges out there and great visibility when using FEL, due to sloping bonnet. One thing I would like to eventually modify is the air intake at the front, clogging the radiator guard & fins..., maybe a snorkel would work, similar to 4WD's. I know the snorkels are connected to the air filter but there should be a way to funnel the air going into the front with enough coverage on the funnel?!