I have two hinged rings for sale. They have 195mm exterior diameter and 152mm interior diameter. The rings are black, felt padded and with no signs of wear outside or inside: brand new. Although the rings bear no mark of who produced them, Joe Nastasi of Parallax Instruments has examined the photo below and confirmed that they are his Parallax-made rings.They were designed especially for a Takahashi AO 130.
Parallax sells "155 mm OD Tubes (Takahashi FS 152, Takahashi TOA-130)" for $195. Anacortes TWB sells similar rings ("Parallax Standard Rings for 6.5" OD Tubes ... Standard Rings for 6.5" OD Tubes (Astro-Physics 155 EDF Refractor)" for $139.
These essentially unused Parallax rings are now $125 PayPal, CONUS only. Together, they weigh almost 4 pounds on the bathroom scales. UPS (5 day) shipping to either coast from Houston should be approximately $11.
I appreciate your interest.