Should I re-download these packs?
Anytime I update a link, yeah. Not only to get the new additions but I often make fixes to some or all of the older skins.
Sometimes I update the packs just for those fixes if they are signifigant enough, if they are minor I wait until I am adding a skin to apply the outstanding tweaks to the rest.
For example this time around I had to fix a bit of out of place color on all the previously done 357th skins.
So always best to just download and overwrite everything, thus ensuring you have the latest.
DW