Here's the Broadway font character set with the example text also shown. As you can see there are numerous differences. So many that it seems doubtful that it is a modified version of Broadway.
The example font certainly has some similarities and may have been inspired by Broadway but there it is decorating a national park ..... so one might conclude that it was done from a font that should be commercially available.
Maybe it's an older letter that was made by Spanjer Bros.
I ran across that same letter style on a school name change
job a while back. We just ordered all new letters from
another mfg. since Spanjer Bros. in no longer in business and
that particular letter style couldn't be found.
Get out the 'ol projector ... dust it off ... do allot of photocopies, cut out each individual letter, set your type ... then blow up your patern ... Trace it out with a pencil ... transfer the patern onto the substrate with carbon paper ... then hand cut it or letter it !!!
LOL!! damn im happy we dont have to go through that anymore!!