From their website it looks like they are open to visiting aircraft, and I thought I saw an open day there a few weeks ago
RAF Leuchars - Flying Info
STRONG ADVICE
Aircraft operators are strongly urged to request a copy of the proposed fees before confirming the booking.
When the booking process has been completed a PPR number will be issued (5 days notice required). Any changes to your booking should be notified to Flt Ops ASAP.
Their website does specifically state
For security reasons, we are unable to publish detailed information on our flying schedules.
So if I were just interested as a spotter I would try book a tower visit and chat to the guys in person. I've been on a couple of military tower visits, they take some organising, but if you're in a group as part of a flying club or whatever it usually goes pretty well.