this may be premature, but if you DO start finding a significant oil drop, there is a pretty great solution to replacing all the seals and whatnot. I have an early 80s Woods bushhog and it wouldn't hold oil for a moment without it all spinning out and leaking out of the gearbox. I replaced the heavy gear oil with "Corn-head grease" from JD and it has been working great for the past 8 years or so. Too solid to leak out, but liquid enough when in use to keep everything cool. No reason to do it if your seals are fine, but it is definitely a cheap solution if that ever comes up. Which now that I've typed all that, I'm sure it won't.
Also, I'm on board with checking before use!
Also, I'm on board with checking before use!