Hello scribnewbie,
IMDL is still in the testing phase for Scribus, so it might not convert perfectly. Adobe was offering 30 day free trial but you do have to remember to cancel! Or you could take the indd to a printshop and ask them how much to collect all the images and copy the text out to a txt file for you. Not sure if there is any online free conversion sites.
Cheers!
mnawij