weird canon FL mount? please help

[terts]

Ok so I feel this is a very silly question, and I am an AVID vintage Canon fan. I am having such a time with this though as I have never seen an FL lens with this type of rear FL mount before...
Any advice is huge and yeah I know it is probably something ridiculous... Maybe I just haven't encountered this version of FL before?
*EDIT* ok so it actually looks like the chrome base ring has the normal mount in there somewhere, or at least the milling for the normal FL mount. Seriously so perplexed by this and cannot find ANYTHING on google showing this type of mount. Was this maybe adapted, or am I just being a cadet?

 

[vintagesnaps]

I can't remember offhand if all the Canon FL mount lenses are breech lock or not. I have a couple of those where you have to turn the metal ring to loosen or tighten to change lenses. Is that the part of the lens you're talking about? Or is there something else different about this one?

 

[terts]

it did end up that the breach lock was seized on there really really nicely. I managed to get the adaptor, looks like it was a bellows adaptor of some sort. Either way returning the lens as there are other issues with it that had not been mentioned.