Advice on existing concrete lintel

[iandandav]

I have a existing concrete (probably reinforced) lintel above the kitchen window opening. Its about 6ft long. I have noticed a few things that concern me. I would like to know what you guys think and possible solutions if any. A few details about the wall the lintel is in.
Cavity wall (Unusual construction)
Inner wall - double thickness of brick to first floor joists Then single thickness (Affected lintel is in this leaf) .
Outer wall single thickness of brick (thinner lintel with no visible cracks)

Above the lintels is about 3 foot of wall to the upstairs window then another lintel above this and then immediately the roof.

The house is an old stone terrace (in exess of 100years) The kitchen is a later extension probably about 30 to 50 years old.

My concerns are the amount of over lap the lintel makes with the wall on the right hand side, 5cm (possibly the same on the left)

There are three fine cracks in the lintel which run all the way up its side and about half to 2/3rds the way accross the bottom of the lintel

Lintel showing location of cracks

Overlap on the right hand side

cracks in more detail

Should I be concerned about the cracks and the lack of overlap. If so what are the solutions.
My thinking is as follows
1) a central pillar to take some of the load
2) RSJ below the lintel
3) extend the wall into the window opening at both sides
4) No need to do anything

 

[cotswoldbuilders]

Id get some acros and strong boys in, remove the lintol and fit a new Catnic or steel in, with minimum 150mm bearing either side.
Your assuming that the lintol is reinforced.

 

[iandandav]

Id get some acros and strong boys in, remove the lintol and fit a new Catnic or steel in, with minimum 150mm bearing either side.
Your assuming that the lintol is reinforced.

Im thinking at 6ft if it wasnt reinforced it would break under its own weight or certainly when weight was added at construction.
edit its just under 7ft