sometimes its easier to make a new saddle or nut than find one that fits, especially as acoustic basses are still rather niche
with a few files and some fine sandpaper its not a massive job to do the saddle, especially if you can just copy the existing one as your starting point. it may take a couple of goes to get right
the nut is just as easy, but is best done with specialist nut files so price goes up - but you will need these even if if buying a ready slotted nut, it would still need the final tweaks
I can probably send you a couple of big chunks (well, massively oversized nut/saddle blanks, but they are rectangular rather than bone shaped) of bone if you want to have a go. I was given a massive stock of the stuff ages ago, its mainly seconds due to colour variation or rough edges, but the blanks are large enough that it can all be trimmed down to what is needed.
one warning though, bone stinks when cut and filed ;)