Hi Ed,
I’m sorry I forgot to put in the bolt hole measurements in my last message.
The mounting flange is somewhat cracked & bent with only three bolt holes remaining intact or close to intact, so the measurements may not be 100% accurate I’m afraid. [and I measured in mm so please bear with me….] I got 11 mm for the diameter of the holes, pretty close to 15/32″; distance between holes on the short side was an estimate due to missing corners – I got ca. 100 mm / 3 15/16″; and the distance between holes on the long side was ca. 110 mm centre to centre of hole or ca. 99 mm edge to edge of hole, so kind of flanking the 4 1/16″ measurement.
I’m also not sure if it is a six bolt hole flange; the centre of one long side is severely cracked when the hole would’ve been but I’m not certain I can see evidence of said hole – were there 5 bolt hole flanges?
Thank you for looking for the Stromberg book. Dogs do have a habit of eating things like that I find! 🙂
Thanks again for your help 🙂