No problem at all, but its expensive. Our glorious postal service discontinued sea mail and only offers 'the good stuff' overseas.
A large flat rate box is $54 to the UK via priority international. I only allowed $15 for shipping. It might be better to add 2 more holders and pack the box to the hilt if you want to pay the extra $39. I calculated them at $12.50 each, so it would be another $25 for 2 more. I'm pretty sure I have more similar ones in the box.