Upgrading Gatherer gear from item level 50

So I've just come back from a very long break and I cannot make sense of how to upgrade my gear. I had Best in Slot item level 50 and the 55 main hand pick, Mammon for mining and Rauni for botany. However, I now cannot see how to upgrade further than this to the newer gear as it's all beyond the ability for me to mine or harvest the required stuff like Redolent Logs and Antumbral rocks. I've scoured the internet and all I can find is current BiS lists and leveling guides. I can't find any guides for upgrading from 50 ilvl gear to the 70 or 75 ilvl main hand stuff. Can someone point me in the right direction please?

ilvl 55 gear is still BiS, just meld it out with materia
there are some new accessories, but they arent necessary

once you hit 370 gathering with your ilvl 50-55 stuff start farming fragrant logs (2 am south shroud) and umbral rocks (6 am south shroud)

you can trade 30 HQ Rocks/Logs for an ilvl 70 BiS Headgear and 60 HQ Rocks/Logs for an ilvl 70 Mainhand tool, both @ mor dhona
Having both ilvl 70 pieces allows you start gathering antumbral rocks (2 am east thana) and redolent logs (6 am central shoroud), which both require 408 gathering

you can exchange 99 NQ of these + roughly 4 mil gil for an ilvl 75 Mainhand tool, same npc as the ilvl 70 tools

Thanks for that ServerCollaps. I just managed to figure that out before you responded. The materia costs though on Ultima server are disgusting. I've already had to dump about 500,000gil for basic materia just to up the skill to 370/332, plus more for all the other things for the new BiS pieces. Not looking forward to that, but thank you for laying it out simply for me.

well its worth it, the thanalan and shroud soil III sell for a lot and there are some other things too, which can be sold pretty good