thought so James...
E10 on the bolts....
tried every combination of torx / metric socket etc i can the last two are mangled.....did eventually manage to get a metric hammered on but rounded eventually again
Cant even grip them and tighten them ( in an attempt to snap them
)
PM me your address. If it gets desperate, I have some "magic" sockets that "cut" into the head of the bolt for a grip, they have NEVER failed yet (presuming you use the right sized one!).
When breaking my Elite, I didn't have a T50 for the cam sprocket bolts, so I removed them using the magic socket, they pulled off some extremely tight bolts, with COMPLETELY round heads

Trying to over tighten them in hope to snap them will give you HUGE troubles, possibly stripped thread in the block (remember how long those K series bolts are)... please don't do this!! 
Good Call James.....i remembered my magic sockets....
Well more my special occasion Snap On`s,,,
Ive just leathered e8 on one, original size e10 not as stated by me above e12.
Then attaced a series of sockets and adaptors and my 2 foot breaker bar, slowley but surely i have the last two out..

So i now have..
Top off
16 shiney tappets removed from head
2 cam sprockets removed from head
2 camshafts removed from head
Ive also got a bottom end of same model car but different vehicle on an engine hoist at the back of the garage...
Now the fun starts 8-)