My good friend Lawrie recently acquired a .22 Howa 55G to compliment his Taiyo Juki Grand Slam.
Finally we got together and took some pictures of them. His .22 Howa appears to be a later production version than my .177 as his has a different white spacer butt pad and a pistol grip cap, together with a slightly different piercer unit and a black trigger.
The Grand Slam bears a remarkable similar profile to the Howa's although the parts are not of the same quality and not as highly finished, it is an extremely nice rifle to use.
Here is the link to the 40+ pictures, hopefully showing some of the details of these scarce Japanese CO2 rifles. If you click onto the little TV screen with the > in it,you will get a slide show.
And yes, that truly awful rear sight is the factory issued item from Howa
A few pictures from the album