This is obviously not the trailhead’s actual address; it’s someone’s house. I found this reference on PhillyFunGuide.com.

Here’s the information from the state natural resources dept. (dcnr.state.pa.us/railtrails IRON CANAL TRAIL&RegID=7, click on the “contact” link)
|Organization|Phoenix Iron Canal and Trails Association|
|Contact|Paul Kusko|
|Street Address|20 Manovan Street|
|City|Phoenixville|
|State|PA|
|ZipCode|19460|
|Phone Number|(610) 933-2548|