Ivanhoe, I hope your sale is successful and these fine guns find new homes. I see two J. Blanch & Sons, and a Masu Brothers, in the sale. Early in this thread I pictured a J. Blanch lever-over-guard, number 4696, similar to one you have at action. The earlier Blanch you have in the sale, with the single-bite, forward-underlever and the grip safety, is a nice early example and very interesting (sadly the auction house did not list the serial number). Here is the picture of lot 117 off the auction site:
Grip safeties are an interesting hold-over from the percussion era, and they are unusual enough on pinfire guns that it is difficult to determine just when makers stopped incorporating this feature. A grip safety makes sense if you are spending time around the muzzle end of loaded barrels, as one might do when loading/unloading a percussion cap gun -- but not so relevant on a breech-loader.
I've encountered three pinfire game guns with grip safeties in about 26 years of searching, so adding your 4 in 44, makes for 7 encountered in 70 combined years of digging... rare indeed. For those not wishing to scroll back into the pages of this thread, here are the three I described earlier:
Harris Holland no. 824
Hugh Snowie no. 3277