The records for the Three-Barrel Gun Co. and Royal Gun Co. have survived. They do have some of the Hollenbeck Gun Co. guns that were still in inventory included in them, but serial number 35 is not there.
The Hollenbeck Gun Co. also produced 20-gauge and even 28-gauge guns. Serial number 122 is a 28 x 28 x .22CF. Here is an ad from the Jan. 25, 1902, issue of
The Sportsmen's Review --
Like this ad, the Hollenbeck catalog I have only offers .22, .25 and .32 caliber rifle barrels. By the first Three-Barrel Gun Co. catalog the .30 WCF is also offered. While the catalogs only mention .25-20 and .25-25 in the records we find all kinds of .25 caliber chamberings -- .25-20 WCF, .25-20 SS, .25-25, .25-35 WCF and .25-36 Marlin
Here is an ad discussing a 20-gauge chambered for 3-inch shells from the September 27, 1902, issue --
