Micro-Scale sells a small bottle of foil adhesive for about $4.00. Sounds a little expensive, but a bottle will last a very long time. It's great for affixing PE. Micro Metal Foil Adhesive is what to look for.
Stevens has it listed on their site, with a $6.50 MSRP (for all sizes). TAM- 87177 Masking Tape for Curves 2mm TAM- 87178 Masking Tape for Curves 3mm TAM- 87179 Masking Tape for Curves 5mm