Steel Lintel Needed for Removing Free Standing Chimney?

[grafferty]

Hi all,

First time poster so go easy! :-)

I've removed the majority of a free standing chimney in a bungalow which ran up the side of a load bearing wall. I have now reached the concrete lintel. Although it's more a concrete platform than a lintel

This shot below is into the loft showing the roof beam resting on the internal wall that the lintel is built in to.

The lintel looks to be keyed into the wall the same way that some of the bricks are further up (the ones sticking out).
My query is can I cut this lintel so it's flush to the wall? WIll this compromise the wall? Or do I look at having a steel put in which seems like overkill to me....any advice?