Well I got a reply back:
Roy,
You will have to reach out to your internet service provider for any questions or firmware requests regarding this product. Comtrend is not allowed to provide support for end users whom are customers of service providers, it’s possible that making changes to your modem will knock you off your providers secure network.
Figured they would say something like that,vr3031 has wifi so dont know if that would be a stumbling point as to building a firmware, last time I tried with a DSL-88U,the source was incomplete, but let me know how you get on and if there is anything i can do to help....
Regards
Roy