Upgrade to a next gen GPU something 7 or 5nm. Don't bother with the other components until you can afford to step up to a next generation cpu/mobo/ram. The very small gain isn't worth it unless you're paying like $20 for both new components that you can make back selling the other ones. I would say the effective value of your upgrade would be like $10. If it costs you more than that including your time, it's probably not worth it to you.
A modern gpu underclocked so it doesn't constantly bottleneck your cpu would be more worth it.