Well, I've found out some more stuff so did a bit of editing, so here it is:
Named patterns used by Remington London (Stub Twist), Twist, Laminated, Boston N. (Horse-shoe pattern), Boston 2 S.J. (large scroll 2 Iron Crolle), Oxford 2 & 4 S.J. (smaller scroll 3 Iron Crolle in several different patterns), Chain J, Etoile 3. B.P., Legia P. (Herring-bone pattern), Washington N 3. B.P. ("Stars & Stripes" or "American Flag Bunting"), Chine P ('mottled'), Ohonon 6 S.T. (similar to Bernard I), and Pieper P.
The Remington Damascus salesman's sample rod is shown on p. 275 of Charles Semmer's
Remington Double Shotguns.
The significance of 'S.J.' (Boston 2 and Oxford 2 & 4) is uncertain, but could be Simonis-Janssen
http://www.littlegun.be/arme%20belge/art...moulin%20gb.htm 'J' could also be one of the Janssen families
http://www.littlegun.be/arme%20belge/artisans%20identifies%20i%20j%20k/a%20janssen%20gb.htm The meaning of 'B.P.' (Washington N and Etoile) is unclear.
Claude Gaier's
Four Centuries of Liege Gunmaking states that Ernest Heuse-Lemoine of Nessonvaux named both "Washington" and "Boston" patterns for the US market.
http://www.littlegun.be/arme%20belge/artisans%20identifies%20h/a%20heuse%20gb.htm Boston N. and Boston 2 first appear on the Model 1878. Boston and Washington patterns are also found on Baker and Ithaca guns.
Damascus barrels with possible Belgian maker's marks include 'HP', frequently found on Oxford 4, likely Henri Pieper
http://www.littlegun.be/arme%20belge/artisans%20identifies%20p/a%20pieper%20en%20tete%20gb.htm Oxford patterns are used from the Model 1876 to the 1900 KED.
An Etoile pattern 1894 Pigeon has a fused 'JP', possibly the mark of J. Pire & Cie, a large munitions firm established in Liege in 1885
http://www.littlegun.be/arme%20belge/artisans%20identifies%20p/a%20pire%20gb.htm Remington graded the damascus barrels on Model 1894 guns as follows:
A Grade: "Two stripe Damascus" (Boston)
B Grade: "Three stripe Damascus" (Oxford and Chain J)
C Grade: "Finer Damascus" (Etoile and Washington)
D Grade: "Very fine (Four stripe) Damascus" (Chine and Ohonon)
E Grade: "Finest Damascus" (Peiper and Legia)
The Model 1900 was offered with Remington steel (K) or Two stripe Damascus (KD).