Nice shroom man!! as far as cloneing it goes your best bet would be to open the stem of it with a scaple or something similar in a sterile area and take a piece of the inside tissue for an LC. Also if you wanted you could give it a good flash dunk in a little H2o2 just to be safe.
The tissue on the inside of the mushie will be sterile so it is not needed just as an added precaution to contams. Nice one btw!!
Oh and from the pics the cake looks just fine but its kinda hard to tell...