It's worth a walk up the valley from Laxey as there are some surface remains and may be some holes... There are quite a few other surface remains of mines around the IOM worth looking at. I asked about mines access a few years (over 10!) on Mine Explorer and got a PM from someone on the IOM who said they had access near Laxey to big pitches to the main stopes. This was probably before any legislation - but who knows - I am sure if you can find the right people then there is still access, just don't have an accident 🙂. The TU group on ME was really useful for this sort of thing, shame it died. Given your profile maybe someone will PM you with details.
(On a slightly off-topic note could you reply to the CCC email I sent...)
Cheers,
Dave