Help: Bonanza Oil Leak?

[Bill Greenwood]

Can anyone offer some specific help? We have an oil and maybe fuel leak in my 1988 Be -36TC Bonanza.
The a&p is a Beech expert, but it it very hard to see some of the engine, it is dark and dirty and wet in more than one spot.
It it a Cont TSIO 520 U B engine, opposed horizontal 6. There is a small amount of oil at the top spark plug well, just a small spot, and it also looks like there is a small green area, like a fuel stain.
The mech thinks the cylinder might be cracked. He has looked inside with a borescope and is not sure; valves and plugs look good, but there is one little spot that looks almost like a spot of carbon, could be a crack?
I have some doubts about this. It seems that if fuel is only going into the cylinder just before combustion, it is not going to leak out as a green liquid. If there is any leak or any crack to be seen, it would be a black carbon streak from the combustion. Does anyone really know about this?
This is cylinder 5, the right front one. We noticed some oil leak coming out the air vents on the lower right side of the cowling and it is wet underneath the cylinder; just hard to see anything specfic there and it is right in the cooling air flow so oil is blown back and down; might even go up as far as I can tell.It seem to be pretty dry up near the alternator which sits in the right front air intake.
I am thinking about asking him to clean the oil off and then run it and see what we get. I don't want to step on his toes when he has 45 years of experience, but I'd like to be sure what is happening, before it is torn down.
I appreciate any solid answers.