The deployed version of BTC Relay is from commit 41753486b770665319f39da55676732b11af40fe
In order to verify the source code please follow the these steps:
serpent compile btcBulkStoreHeaders.se > compiled.evm
Here's how to use Geth console to obtain the evm. The receipt is used to guarantee that the tx hash provided is the one that created the BTC Relay contract (see contractAddress property of the receipt).
> tx='0xa51ce97bd9a1e7be15c0e7bd2782967239cb9bc015c6088c37cc8931c8283f17' > objTx = eth.getTransaction(tx) > objTx.input
Compare objTx.input with the contents of compiled.evm and you will see that they match identically (except for 0x at the front of objTx.input)
The version of the Serpent compiler used is commit 51ee60857fe53c871fa916ef66fc1b4255bb9433