I'd imagine the newer tools support any older OFW as well I don't think it should be an issue. When I used older tools on newer OFW it only gave me a Hash error, I read that I could have technically ignored it without any problems. I still waited for the newer tool and it went ahead no problem.
You could hypothetically upgrade to 4.76 OFW and then use your 4.76 Norinspector and PS3DumpChecker, I think either way it would be the same. Remember to used HxD to compare the dumps too