None that won't cost you probably 10x more than the cost of buying an IP NVR.

You can get a dirt cheap NVR, then feed that into a HDMI to composite converter and that into the analog DVR,

Or just use the chean NVR as an NVR and possibly have it connect to the analog DVR's feeds to show those on the TV as well, and then retire the analog one when all its cameras are upgraded.