There is a page similar to that, in Kennett's 1970 Gun Digest article, that includes marks from the proof house in Paris. It is a great article, and he did a series on them for European proof houses in the same periodical, published in different years.
Wild Cattle, if you can get a picture of the barrel flats and proofmarks on that lunette Ideal, it would be fantastic. I'll cautiously note that if it was proofed for anything other than powder T, say PM, PJ, or PS, it would likely be unwise to run off to Wal Mart and procure a box of whatever 2 3/4" is for sale today to shoot in it. Kennett noted in 1970, that it was often difficult for the 12,000 PSI minimum to be reached with the powders used prior to powder T. Further, even if it was proofed for powder T, that is an old, and light gun, and it would be wise to subject it only to lower pressure ammunition. Ere on the side of caution, I always say.
Best,
Ted
