This is the 21pin tender version of Bachmann's A2, which makes fitting DCC sound, with a decent speaker and good stay-alive a doddle...
Here is the intended kit laid out as desired, with the pair of 1000uF capacitor joined in parallel.
So, commence the installation, connecting the LS26X20X08-1W Dumbo speaker wires to the provided solder tabs in the tender.
MX644D decoder goes in with wires attached ready for the stay-alive capacitors.
All wiring complete.
Some holes drilled under the coal load for better sound escape.
Tender top back on, and all fits in easily.