I am not an expert but I have a 2r with Lunette trigger guard. The higher the number the higher the grade. Mine is from around 1900. I have seen a grade 6 and it was more ornate then yours and the lumps did not show through the bottom. I would guess yours is between a 3&5 it should say on the lumps or flats etc.
I paid $1000 for a pristine exaple with 100% case color and bluing but a 2r. I recently looked at a 3r for $1200 in very good condition. Yours I think would sell for between $1200-1500.
If you wwant to sell it please let me know.

Jeff G.
njscuba1@optonline.net