purple,
5 pages like that isn't enough to get you a penalty, although 6000 thin/dupe pages like that would be enough to put your site in a class with spam sites. So the question is--how do you deal with those other 5995 pages when the time comes to put them back up, if it comes. I'd be thinking of breaking them down first by manfacturer (with a strong page on your unlocking service for each one) then by model type (with a strong page on your unlocking service for each one) and then you might start breaking them down by specific model number. With so many new model numbers coming out each year, it seems like you'd keep your hands full creating content for just the new ones, let alone old ones but you could work your way back in priority of those that give you the most business.
As far as the content itself, it could be videos about how the consumer could unlock each specific one themselves, interviews with owners of unlocked phones, information about the phones themselves (development history, carriers that sell them, sales specs, technical specs, OS's used....) There's a whole ocean of information you could be giving your audience that pertains to the genre of cell phones, unlocking, carriers, mobile devices, manufactures, OS's, etc. Standardize on a number of specific points of data from those areas that you think best gives the audience a picture of your brand's philosophy about being in business and include them in the content for each new page you create. Remember, you've got to think like a publisher if you're going to pull yourself out of that penalty.