Since I can't get a hold of Josef, I have decided to post here with a copy of the updated ttdpbase[w].grf.
As of the next nightly, the minor version for ttdpbase will have increased because of the new sprites for marking tracks on slopes in a pbs junction (r1486 and r1487).
This will only affect the trunk builds as none of those fixes are in the 2.5 stable branch.
At the present time, I have no plans to back port these fixes.
If you want to use this for your grfs, you might want to consult the Wiki's Action5 page.
Hopefully, when me and Oskar get round to writing newRoutes, this basic support should become obsolete.

[Edit] Due to the new Action5 type, this is incompatible with the stable builds and anything pre r1487. Sorry.

[Edit 2] See post below for the latest version which should work happily with older versions.

[Editted By Lakie] I'll make this thread a sticky for a few days since it is fairly important.
Thanks for your time,
~ Lakie