Of course, all plastic bits were lost in the chemical process (and some others still wonder why some of us still stick to barbarious relics like precious metals)
I've found iso struggles with anything with a gloss prime finish personally, but like you say normally you can just prime over a prime if it isn't caked on.I've found it struggles with some primers on a few things I've bought on eBay. For example on the night goblins, half of them came out like brand new, the other half lost some of the acrylic paint but the black primer stayed behind and seemed to hold onto some of the acrylics. Which is why they stayed in for a year, to see if the others would eventually come clean. They're still easily re-painted though.
Topic has been hijackedTo be honest, I didn't care about these marines plastic bits. My intent was to convert the miniatures to make them more suited to an underhive setting, and less "army regular" looking.
But thank you all for your tips regarding appropriate paint stripper for plastic parts. That will be very useful a day or another.