I've always loved this version; probably my favourite DD remake for OpenBOR. Love the new Marian character in this update!
For the previous 4.0.4 version, I actually made a private patch (for personal use, never uploaded it anywhere) that improved Linda with some sprite edits and code tweaks. With that, the original "blonde afro" DD1 Linda was a playable character choice (actually, the DD1 lady is "Linda" aka "Linda Lash" while the DD2 mohawk girl should be "Cindy", something I also changed in my mod, as well as fixing the Abobo-Bolo naming too).
It all worked really well, even the ending, however I am a now bit lost how to update my mod/patch for v5.1.1, especially with the new character select screen. Can you help?
Also or alternatively, I'd be happy to share my sprite edits if you want to make DD1 Linda an official playable character. I also made it so she can use dynamite and knives, as well as being able to performing spin kicks like DD2 Linda. For both DD1 and DD2 Linda versions, I added the ability to perform jump kicks, elbow strikes and climb sideways with more custom sprite edits. I added a bunch of palette swaps for them too.
Oh, and I also fixed Williams' sprites since a few had miscolored pixels held over from their arcade days!
Please let me know if you're able to give me a hand, or as I said, interested in using my sprites and new moves (the latter will probably need their code tweaked for the new 5.1.1 changes).
Regardless, thanks again for this awesome game!