Kenwood VR-4080 External IR Transmitter / Reciver

I am looking for a Kenwood “IR-9991” IR Reciver.
The Kenwood A/V Reciver, VR-4080 uses a remote that is a combination of RF and IR.
The IR-9991 will allow the system to be controlled with IR only, allowing the use of modern “unifying remotes”.

Anyone have one for sale or know of a substitute?