Discovery 300tdi head gasket replacement Help!!!!

Hi on my journey of Discovery!!!!! 300tdi lol head gasket failed now removed and it is a 3 hole fibre gasket type .... I bought an all metal 1.5mm new head gasket as I have been told they don't compress as much as a fibre type? So here is my question? .... I took the head to be pressure tested and it came back ''all ok'' .... so I had it skimmed and it took 0.5mm to get it true .... This looks like a heck of a lot so will I have enough clearance if I re fit the head? Ie valves injectors etc? .... I can see that the valves are still about 1.00mm ish sunk into the head .... as I don't know how many times this head has been skimmed please could an expert tel me how to calculated if my head is still ok to re fit ?
Thanks for your help .... cheers

https://www.google.co.uk/url?sa=t&r...wn_checking/&usg=AOvVaw1G41OBoD5NHR3Sv0wWfuaB
info is in the link above to check the valves, the fact its had so be skimmed means its possible it will easily warp again,personally id have used a composite gasket on a 300tdi

Hi ...thank you