Loads of OSR modules include new cool and atmospheric spells that can be learned or casted from a scroll or a grimuar. There's plenty of those out there.
The problem in porting them to FL is how restrictive its magic system is. By choosing a school in FL you grant yourself access to just a small chunk of the spells (which is fine in it's own rights), but in most OSR systems we have only one school - MAGIC USER that is able to learn all of the spells from a lvl he is.
How would you port those spells? Maybe split the xp cost of the talent to see how much would a single spell cost or say perhaps that you can learn and cast any spell (of your lvl) but it is always unsafe? Did anyone play with those ideas before?