Which organ builder did your father work for? We have organs by Cassavant Frere in the Twin Cities and greater Minnesota, there most recent instrument is in Bemidji. There is also a fine instrument of theirs in Grand Forks ND, which I recorded on two occasions. We have a fine instrument By Gabriel Kney at St. Thomas University in St. Paul. As far as I know both of those are still in business.
I'm familiar with Casavant Frères as they are one of the few remaining organ companies in Canada. They rebuilt the pipe organ in our church several years ago. Brings a smile to my face because my father complained about the original organ being too airy and not sounding full. The rebuild was a noticeable improvement. This is the rebuilt organ at Wesley-Knox United Church in London, Ontario:
My father worked for Knoch Organ Company just outside of London. The company was originally just my father and Werner Knoch. They did install organs in the U.S. as I recall him staying in Montana for a job. That would have been over 50 years ago. The company became Knoch Manufacturing and around the time my father retired they had almost 100 employees. It was purchased by an American who didn't invest in the company like Werner Knoch did and closed shop a few years ago. I worked some summers there as a student and was fortunate enough to join my father on one last organ service call. It was a church organ in Stratford, Ontario, home of the Stratford Festival Theatre. It was a real pleasure getting out of the noisy machine shop and working in a quiet church cleaning and tuning pipes for two months.
(Wow, just by chance I found an entry in pipeorgandatabase.org for that organ
. Installed in 1962 by Knoch Organ Company it is a Walcker Opus 4. There is a link at the bottom with more details and photos. I helped to take out ALL of those pipes and clean and reinstall them.)
My grandfather worked in Vienna out of his shop in the Prater (the city park with the large ferris wheel). I could even show you the shop from Google street view
It's sad to see the windows boarded up now, though. The house was built by my great grandfather and then they added on the organ shop, a maintenance shop for the wooden row boats they rented on the river (Heustadlwasser) and then a variety store that my great uncle ran. My grandfather had done repairs on the organ in the Vienna Music Hall (Musikverein), the chapel organ at the university and once restored a practice organ used by the composer Franz Liszt.
I have some negatives of his work from a smaller organ although I'm not sure which town or church. The photo of the console has a plaque on the left bearing his name.