UK Degree Honours - add GPA?

So I have completed a UK undergraduate degree at a UK top target (think oxbridge, LSE, Imperial College) but I was agonisingly close to the top score (first class honours). I graduated with upper second honours I don't know what to do with putting this on the CV now.

For this who are unfamilar with the UK system this is a brief summary:

It is significantly easier to get an A than a first honours. It is significantly easier to get a second upper honours than a B+

So any upper second honours can be a wash of 3.0-3.7 GPA but there is no elaboration on the grade in the transcripts nor does any UK uni do a proper conversion. My average is around an A- I believe.

Most graduate jobs ask for a upper second honours but I realise in the US they ask for 3.5 which is solid A- territory.

I do have a graduate job (BB MO 3 year programme in London) which I have met the offer for, but I am concerned about further career progression or bschool. If doing internal transfers, do they look at your GPA/Grade or is it just your networking and work performance?

Any help would be much appreciated. Thanks in advance!