This paddle bladed butter knife is from Birks Silver and is part of the Regency Plate line. It began production in 1997 and is still being manufactured. This classic pattern is Tudor, which is identical to the Birks sterling pattern, Saxon. If you are collecting Saxon and the budget is tight, you can intermix Tudor and no one will know unless they pick up the magnifying lens.
This butter knife is 6 7/8 inches and is in excellent condition. I have other pieces in the same pattern that are as new.