Spike gets cursed with soul instead of Angel

Hi, I'm looking for a fic I read some time ago and it's driving me nuts that I can't find it anymore.

If I remember correctly Spike was cursed with the soul instead of Angelus because of some type of mix up with the spell. Angelus, Darla and Dru then spend about three years torturing Spike because of that until the Kalderash finally managed to curse the vampire they originally intended to. Angel then freed Spike and they parted ways for about a century.
The story actually takes place mostly in Sunnydale where Buffy encounters a Spike who's been demon hunting for all that time. I'm pretty sure most of Season 1 happened already and Buffy is (at first only of course) involved with Angel, but I'm really not certain.

Thanks for any help with finding this one.

PS I'm also pretty sure that in the hundred years Spike had the soul he manged to get it anchored some way (and Angel didn't, I think)

Avocation by Enigmaticblue; found at Elysian Fields and Nocturnal Light.

That's it! Thank you soii!