Bachmann collett non dcc ready

[Gwrpannier]

I'm looking to fit dcc sound to a Bachmann collett goods which is not dcc ready.im wanting to fit the decoder and speaker in the tender.could someone please point me in the right direction for a suitable way of wiring from the loco to the tender.harness/micro plug etc.

[Free At Last]

I used these for connections between loco and tender... https://www.railwayscenics.com/wired-miniature-connector-sets-c-20_22_350.html