I was hoping someone would know the typeface used for this heading.


That |G| is highly unusual for a gothic. Does your sample date from the 1920s?
I’m not sure what the original metal typeface was, but here are a few digital typefaces (with a bit of surgery on the crossbar of the |G|) that could help you replicate the look:
http://www.myfonts.com/fonts/linotype/alternate-gothic-lt/
http://www.myfonts.com/fonts/flat-it/rama-gothic/
http://www.felicianotypefoundry.com/cms/fonts/grotzec-condensed
https://klim.co.nz/retail-fonts/founders-grotesk-condensed/
Founders Grotesk is definitely the best option here. I'd like to add a ready-to-go option with Penny Lane which has a crossbarless /G but you'd have to artificially compress it (ouch).
Captured from web.archive.org on 17 Mar 2015. view this capture
After considering various options I would suggest as the closest substitute, KLIM's Founders Grotesk Extra Condensed Medium, which is based on a 1912 Miller & Richard specimen of No.7 Grotesque all-caps.
For a closer match clip the bar on _G_
Also compare to the Semibold weight
Don