It is not a fuse box and they are not fuses. It is a consumer unit and they are MCBs.
There appear to be 2 unused 32a MCBs there or at least unlabelled.
You can get fuse holders for consumer units
however the main problem is a consumer unit is a type tested distribution unit for use when an ordinary person is in control, and the type testing means the manufacturer has to authorise the use of all parts used inside the consumer unit. Schneider Electric took over GET in November 2006 as to what is still available I don't know.
However it does not matter how much common sense says you can get other makes MCB's or fuse holders to fit, a scheme member electrician has to follow the BS7671 book, as he has signed a contract with his scheme provider to do that, and he would need permission to not follow BS7671 so he wants to follow it when ever he can, it also is likely required by his insurance.
When I replaced mine, the RBCO's were less than £10 each, the old Wylex box a MCB costs around £11 so to upgrade to all RCBO with new box, was very little more than fitting MCB's in the old box, so one has to some times bite the bullet and fit new rather than trying to muggle on with the old.
I am sure if you really want, there is a way to fit hob without changing board, but the question has to be, is it worth doing, as next time you will have it all over again. Not sure when type testing came in? However over the years it has changed, I think 1999 but not sure, before then it was not a consumer unit.
