had an idea that Styrene sheeting was polystyrene whereas ABS is harder.
Misused term like "Fibre Glass" and all vacuum cleaners are "Hoovers" and all ball pens are "Biro's"
"Poly"styrene was the original "Plastic" after Bakelite(??) that most rigid plastic goods were made from until the Engineering plastics started to appear.
Acrylonitrile
Butedine
Sstyrene was/is a more bounceable version of the original Poly. and lots of the original moldings seen on our toys were a pink colour, found when you scraped the Chrome plating off it as ABS was THE plateable plastic.
For gluing the two types, One of the Keytones (MEK) is better than Cyano as it is a
Solvent for Polystyrene and good ole' Balsa cement for ABS.
Both forms of sheet
plastic have been used for Vac (Vacuum) formings, another misused term.
Regards Ian