All I know about the old tunnels is that for many years they were used as a mushroom farm, and now maybe wine storage.
I also remember in the late '80s someone (from out of town) taking a route choice through the currently-functioning train tunnel on the Sleeps Hill orienteering map!
I havent googled her story to confirm but we are talking early 1900's so way before either of us were born Jenny. She also talked about its use for a mushroom farm and people taking shortcuts through the tunnel. But considering the frequency
of trains and the gaps you had to shelter
in along the tunnel walls i wasnt interested in a short cut!
Sheps is one of my favourite places to run because once in that valley, you could have no idea that there is an entire city out there...don't think I've ever seen any koalas in there either, but did once encounter a kangaroo and wondered how many roads it'd had to cross to get there!