A few days ago i found this pages that still sell the ultrabay connector, https://www.onlinecomponents.com/te-connectivity-amp-brand/21990151-44869647.html?utm_source=octopart&utm_medium=inventoryrefferal&utm_campaign=octopart&ref=OctopartFeed, https://www.verical.com/pd/te-connectivity-power-connector-2199015-1-4586152?utm_campaign=octopart_2018&utm_currency=USD&utm_keyword=2199015-1&utm_medium=aggregator&utm_content=inv_listing&utm_source=octopart.
Saddly i dont have the skills nor time time to try and make an adapter, but i would be willing to buy a working one from someone.