Advice on injector blow-by on a TS2

[Fiddler70]

Hello folks, I am new here and have just bought a TS2 Genset 7KW. it starts and runs ok but one injector is blowing by.

I am wondering a few things, so please chime in with any advice.

Is it worth sorting out? 
Is it a lot of work to remove the injector and replace the copper washer? Would that  even fix the issue?

Just trying to gauge what if anything to do about it. Really hoping this task has been done a few times by the forum members so will have first hand experience. Thanks in advance for suggestions

[Fiddler70]

So i decided to go for it - simple copper washer replacement... or so I thought... Removed injector, washer had a bit split in it... strange... then I saw the injector port on the head had a hairline crack spreading outwards... Bugger! New head needed... But luck would have it - I found one the same day.. i am NEVER that lucky usually!  and so the great head swap has begun... waiting on gasket set now.

For 29,000 hours it looks pretty clean I'd say!