Study notes:
Recent study with advanced students who have kindly shared there knowledge with me have indicated that this is most likely a work of the Nidai. More info to come ...
This kozuka is similar to the workmanship of Yujo, the first mainline master (1440-1512) shown below. The character of the nanako, the nanako placement, use of gold in the design, manner of the branches and overall feel of the piece are similar. Please see the reference photo below and compare it to this kozuka.