I'm going to do the same. Based on OVMS project I prepared CAN frames which should comes from BMS. Because a workload this project must wait to June, but I hope that i can do this...The speedometer should comes from Sevcon, so only a part of dashboard messages comes from battery.
Please tell me if You have any success in Your project. Maybe You can share Your knowledge? I have good knowledge about the batteries at all (more than 3 years in battery supplier company in R&D), so maybe I han help You with another issues (sevcon, dtv customer etc?) Please send me materials acc Your existing status of the project