Zoom, I have a sporterized A303 30/06 that Paul Jaeger built for my grandfather back in the 1950's. It was my first hunting rifle. I just refinished it earlier this year (it got some moisture damage a few years ago when I let my dad store it along with some others while I was moving/traveling). It took me a great deal of time to trace down any info about where I could find some replacement 1" scope rings for his custom scope mount.
His nephew owns New England Custom Guns,and might be able to help you with any questions you have,as he studied under Paul when he came to the USA from Germany.
That is a great looking shotgun,very nice engraving. My A303 is pretty plain compared to it,but it was built to be used and it has been used alot throughout the years. THB