Appears to be a Mk3 Seeley, but looks strange under the tank. My bike has much shorter manifolds, but the throttle cables are still bent very closely under the bottom of the tank. My motor is as far forward as I can sensibly get it. Also I don't use that ladder in front of the motor, I use a gusseted bent chrome moly tube. One of the things Bill Horsman mentioned about the Mk3 G50 he used to race successfully, is he could feel the front of the bike walking when he pushed it hard at speed. My Mk3 stays very rigid.