You could have connected your rotary phone to the HT-502 then pointed the proxy at the OBi200.
You can still do this to use as 2 more phone ports on the OBi200.
Post if you're interested and I'll show you how.
Very interested in this! I have an Obi110 now but realize I should upgrade. I collect vintage phones and want to have pulse dialing work for some of my rotary pieces, which right now can answer but not dial out.
On my dream list is a way to have the whole house system work like a PBX so you can call from one phone to another, and I'd love to get some of those old phones with hold and transfer buttons on the base to actually work, so you can transfer calls from phone to phone ...