This plastic Deathwatch Space Marine was a very simple conversion. To achieve that Deathwatch look the model uses a plastic deathwatch style shoulder pad from the space marine command squad sprue along with a vehicle crew head from the space marine vehicle sprue. A scope from the space marine tactical squad boxed set was added to the boltgun. The rest of the model just uses normal space marine parts.
Other ideas for all plastic deathwatch are using the devestator heavy bolter and the bare head with the bionic eye from the commander sprue makes a good alternative head.