As a reference guide, I found this TX / RX compatibility chart online. As we are using the RM06 433MHz ASK RX modules it confirms that we need the BX-TM01 / BX-TM05 TX modules. This chart may help someone identify if they are about to buy a correct (or incorrect) matching module, as there are "many" out there on eBay...
Regards, Mark R
Regards, Mark R

