We recently visited the Soviet space program exhibition at The Science Museum in London. There were a pair of intact Vostok reentry vehicles on display. The ablative coating was made out of wood. No snazzy ceramics for the Russians. And it hadn’t lost a huge amount of its surface either, just a bit of charring. 
If you’re visiting The Science Museum (for free), it’s worth the entry fee to the Cosmonauts exhibition. Today is your last chance. There’s an intact LK there too.
