How could I build 'Apex Armor Sentinel Prime'?

Titans Return Sentinel Prime is the figure which got me back into collecting, opening the rabbit hole which has left my pockets bleeding and crying. In spite of it's clear status as an Astrotrain pretool, the figure appealed to me on the basis that it looked based off his appearance in Megatron Origin. However anyone who has read said comics will remember this:

Sadly no third party upgrade kit ever manifested itself (probably because the figure wasn't popular?) and as such I've been left wondering how to make my own Apex Armor, give or take a creative liberty or ten. My best guess would be to make some snap-on armor which attach to the 5mm port of his leg for the leg gun and something around his shoulder and back which would have many 5mm ports. Beyond that I'm completely in the dark especially because this apparently has not been attempted as a custom yet or, if it has, I've never seen pics.
Any ideas?

Sadly no third party upgrade kit ever manifested itself (probably because the figure wasn't popular?) and as such I've been left wondering how to make my own Apex Armor, give or take a creative liberty or ten. My best guess would be to make some snap-on armor which attach to the 5mm port of his leg for the leg gun and something around his shoulder and back which would have many 5mm ports. Beyond that I'm completely in the dark especially because this apparently has not been attempted as a custom yet or, if it has, I've never seen pics.
Any ideas?