Hi,
Several of the ‘old’ tilesets were added some years ago, and haven’t been updated for a long time.
There is no way to ‘fix’ them, unless you want to add all those missing tiles yourself which, I believe, you are perfectly entitled to do, as long as you give credit to the original tileset authors in your work.
The alternative is to start using one of the more recent tilesets, such as ChestHole or MShockModded. These are the most up-to-date tilesets, with authors who are still active on a near-daily basis. Retrodays recently received a massive update too. That one used to be my favourite, but now I mainly use MShockModded 32…
Hope this helps… 