Its not always about the hopeful benefits of a no seized up functioning RCD at the time of fault, but having old 3036 rewireable fuses is a pain in the bum for most people. So if anything I would want shot of them for MCB's, but thats me.
What I say to people is this who have old 3036 boards.
"What you have is on the old side, but I am not suggesting its dangerous. Just because its old doesn't mean its defunct and needs ripping out. Its like the wires running round your house, they may be old, but unless they show signs of deterioration why replace them. The only time I would advise you to perhaps look at rewiring part of a circuit or house is when you want to make more changes to the circuit which out weigh the time to just rewire the circuit.
The main difference between your old rewireable fuse box and a brand new latest specification Hager board, be it metal or plastic is that you have no RCD protection at the moment, which is going to help save your life in the event of a fault, and you have fuses that you have to rewire instead of just push a switch back up.
The new one also looks a lot nicer and will be properly labelled so you know which circuit is which.
If you would like to continue with your old fuse box, thats fine, but should you want to add any more circuits, you may need to then think about upgrading it as you have no space left in it, and the other issue is, should you want any electrical work carried out in your house such as new socket outlets and cables flush in the wall and so on, then unfortunately this work would need to be RCD protected, which then leads you back down the new consumer unit route.
Should you wish to upgrade, you have two options, you can either have a plastic consumer unit, or a metal consumer unit, both of which are excellent bits of kit, I only fit good quality products, the board I would fit would be made by a French company called Hager, they are very good, unfortunately some people charge the earth and fit cheap tat, Ill probably charge you less and will certainly fit a much better consumer unit.
The option of metal or plastic is basically to do with the latest Amd 3 of the regulations, although i don't have to fit a metal one at present, I do like to give people the choice. As of January next year, consumer units have to be made out of a non-combustible material, and the general concensus at present is that the only non combustible material is metal, but this is open to debate, but thats how it is at present. The reason that its going this way is because of fuse box fires where conductors have not been terminated properly, generally this is caused by inexperienced electricians over hardware failure. the point of it is, the fire would hopefully be contained within the consumer unit instead of it melt and spread.
If it was me I would upgrade the fuse box to the latest spec, I notice you have small children running around, and I would say that having RCD protection on your sockets is going to be better for them than not doing so should they poke something in a socket. Only last week (this is dead true by the way) my son had my keys and poked one in the earth terminal fully in at the top and switched it on, it would have only taken for him to poke another one in the live at the bottom and it could have been potentially fatal should there have been no RCD. An RCD is not there to be relied up on, but more of a "its better to have it than not" in the event of a fault.
Anyway, ill leave it with you, if you want that swapping out for a new one let me know."