The 54-year-old actress played Princess Margaret in season three and four of the hit Netflix show. She's now handed over the role to successor Lesley Manville as the royal drama continues telling its chronological tale, but managed to take some souvenirs from the set before the gig came to an end.
"I got loads of stuff - it's all going on eBay. I've got lots of pearls, though I'll send those back," she told Britain's The Sun newspaper. "But we got real, proper props. There was this lighter which was fantastically heavy - it was pure gold, it was ridiculous."
"I was like, 'How much did this cost?' And they told me and it was just shocking."
Helena became synonymous with the cigarette holder Margaret is always seen with thanks to her role in the show and, in another interview with Radio Times magazine, the British star said she should use the accessory as a baton to pass to Lesley.
"I feel like I should be handing over a baton, like this race we are all running," she smiled. "With Lesley, I feel like I should hand the cigarette holder that I used as a baton. Here you are, over to you!"
"She's going to have a great time with her and I'm so chuffed it's her and she's a great actress and she'll have great fun."