RFXCom Door chime: Byron DBY 22322

Hi Guys,

I am trying to get my door bell working in Openhab 4.04
Make: Byron
Link to : Vendor Page

I have RFXTRX Pro XL1 with latest firmware (1048).
RFXMgr gives this event when I press the doorbell:

30/12/2023 12:56:54:454= 0816070039CC85D340
Packettype = Chime
subtype = Byron DBY
Sequence nbr = 0
ID = 39CC85D3 decimal:969704915
Signal level = 4 -88dBm

I found this error in the OpenHab logs, but it is only comes occasionally:

2023-12-30 13:24:05.836 [ERROR] [internal.handler.RFXComBridgeHandler] - Error occurred during packet receiving, data: 081607130000000060
org.openhab.binding.rfxcom.internal.exceptions.RFXComUnsupportedValueException: Unsupported value '7' for SubType
	at org.openhab.binding.rfxcom.internal.messages.ByteEnumUtil.fromByte(ByteEnumUtil.java:37) ~[?:?]
	at org.openhab.binding.rfxcom.internal.messages.RFXComChimeMessage.encodeMessage(RFXComChimeMessage.java:84) ~[?:?]
	at org.openhab.binding.rfxcom.internal.messages.RFXComChimeMessage.<init>(RFXComChimeMessage.java:64) ~[?:?]
	at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
	at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77) ~[?:?]
	at jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:?]
	at java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499) ~[?:?]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:480) ~[?:?]
	at org.openhab.binding.rfxcom.internal.messages.RFXComMessageFactoryImpl.createMessage(RFXComMessageFactoryImpl.java:133) ~[?:?]
	at org.openhab.binding.rfxcom.internal.handler.RFXComBridgeHandler$MessageListener.packetReceived(RFXComBridgeHandler.java:259) ~[?:?]
	at org.openhab.binding.rfxcom.internal.connector.RFXComBaseConnector.sendMsgToListeners(RFXComBaseConnector.java:49) ~[?:?]
	at org.openhab.binding.rfxcom.internal.connector.RFXComStreamReader.run(RFXComStreamReader.java:71) ~[?:?]

I found this post: RFX Byron BY - Add-ons / Bindings - openHAB Community
@pauli_anttila worked on something similar back in 2021 on a different model of Byron door chime, not sure if this is compatible?

Can someone explain how I go about adding this myself?

Thanks in advance for any pointers!
Will