Looking good! For a heavy steampunk look you can even put these on the pipe joins on the vertical and horizontal pipes:
https://www.builders.co.za/Plumbing/Copper-Pipes-&-Fittings/Compression-Fittings/Saffer-15mm-Copper-to-Copper-Slip-Coupler-Compression-Fitting/p/000000000000286963?gclid=Cj0KCQjwibDXBRCyARIsAFHp4fpeparrodWcJPWs83ysOlh7kukUeIslxyWQOPuCSIZxo-9ZrbyJ5F4aAujTEALw_wcB
(well, not that size, but you know what I mean)
Since you don't need them to actually "join" the pipe but more for aesthetics, you can even grind them in half (lengthwise) and glue/epoxy them on from either side.
Maybe on my next one. Gonna make a small one for my nephew