Just ordered my Plutonium Edition last night from the BTTF shop along with the DeLorean key and they're already on the way! I heard and I could be wrong, but the Styrofoam flux capacitor is a base display for the plutonium bar. Maybe.
If the key was put in the box with all the other props it could imply that after the delorean was hit by the train and all the other stuff that happens at the end of part 3 marty could see the key an key chain in amongst the wreckage and take it as another Momento of his travels with doc
This is the original seller, Doctor Collector: us.doctorcollector.com/shop-by-brand/back-to-the-future/back-to-the-future-time-travel-memories/ But it looks like they are also selling them through Amazon now: www.amazon.com/Doctor-Collector-Future-Memories-Standard/dp/B0966SFBT5/ref=asc_df_B0966SFBT5/?tag=hyprod-20&linkCode=df0&hvadid=545942253969&hvpos=&hvnetw=g&hvrand=1272554708738674641&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031202&hvtargid=pla-1599433804512&psc=1
Here is the Doctor Collector link: us.doctorcollector.com/shop-by-brand/back-to-the-future/back-to-the-future-delorean-key-replica/ Here it is on Amazon: www.amazon.com/Doctor-Collector-DCBTTF06-Delorean-Replica/dp/B08LNRDNZM/ref=pd_bxgy_sccl_2/147-8128865-8129730?pd_rd_w=s0pOd&content-id=amzn1.sym.43d28dfc-aa4f-4ef6-b591-5ab7095e137f&pf_rd_p=43d28dfc-aa4f-4ef6-b591-5ab7095e137f&pf_rd_r=YJ46K9PT7JA2EJGC8ZET&pd_rd_wg=9nTnM&pd_rd_r=64c54117-8b19-4f62-9f44-bbd866ed2b6e&pd_rd_i=B08LNRDNZM&psc=1
