Can a regular builder help sort this

[Coffeesnob11]

I stripped out tge 1970's concrete fireplace in my 1960's house and discovered the middle of the lintl has been cut away. The last owners were here for 45 years so the house has stood successfully. I got a full structural survey when I bought it bit of course the surveyor wouldn't have been able to see this because it was hidden and blocked up.
My question is would a regular builder be able to sort this or do I need a specific trade?

Regular general builder I think

This would be something quite straight forward you could do yourself, if you're that way inclined! You can buy lintels at builders merchants, tile slates and cement to level & fix it in, quite easy, but it's definitely a regular builder required if you do not want to do it yourself

just make sure the lintel is up to the job - almost any builder can do it -not sure why its cut out though - u got pics from before

I only have a before video but this is a screen shot, it was hidden behind concrete fake bricks and blocked up.

Are you sure there's not a lintel above it behind the plaster?

I agree with @PreFabBroadBean , it looks to me like there is another lintel above the gap that is bearing the load. I would definitely want to get a builder to look at it though, and assuming all is well, it won't be an expensive job.