Questions on old boker

[buckkiller58]

hello, picked this one up the other day and cant find one exactly like it, but i bet you guys can! Its a 9293 but has what I'm calling a half fishtail bolster? and haven't seen that yet. Has plain tree shield, no trademark. Also tang has been double stamped (Numbers and Tree) I know its nothing special, just wondering if these oddities can tell approximate age or enhance the value? thanks, RED