Hygena APM 6812 thermostat

Hi, I have purchased a replacement thermostat Stock Code 45X5631 from AWS Appliance Spares in Norwich. I noted which lead was connected to which contact on the old thermostat but the design of the new one is slightly different from that being replaced and the electrical contact layout has been changed. Of course I have thrown away the old one. On the new one the brass contacts do not have earth, live in/live out symbols. Instead they have the numbers 2, 3 and 6 stamped into them. Can anyone please tell me which lead should be connected to which contact?

For what it is worth, there is a 2K Ohm 4 band resistor between two of the contacts (2 and 3) and and there is no electrical connectivity between those two contacts and the third (marked 6). I am guessing that “6” is the connector for the green and yellow earth lead, but lost as to which way round to connect the black lead (with a simple metal lug connector at its end) and the brown lead (surrounded at its end in a plastic rectangular case) to “2” and “3”.

I’d be grateful for any help. Thanks.