The Roseburrow Prototype is a mission item. An early mechanical prototype by Esmund Roseburrow that could be used to upgrade non-chemical firing mechanisms. It is kept in a secure exhibit case on the second floor of the Conservatory.
To access the prototype, you must first enter the Security Room behind the exhibit, locate a Rewire Tool if you don't already have one, and rewire the Security Panel. This allows unhindered access to the item. If you do not rewire the panel, the instant you enter the exhibit area, four metal shutters come down trapping you inside.
After obtaining the prototype, return to the Black Market Shop for a reward.