your work seems to be without much shading. i'd agree with tfacarving. i'd call your style line engraving as well. thanks for joining and showing yer work.
if you cant find an adaptor, it should be easy enough to fashion one using a small wood lathe. no lathe, you can make one of plastic or wood by careful shaping using a drillpress. any well equipped plumbing shop should be able to conjur up an affordable adaptor to do this. you'll need an...
what material are you practicing on ? my advice is to use copper at first. esp. with the knife graver. these are buggers on the harder metals. try a 120 graver. these can produce extremely fine cuts in a wide variety of materials. look at sams' tutorial on fine shading. he uses power assisted...
the method would depend on how deep the scratches, as well as how close to the actual engraving they are. without a good closeup foto, not sure how, or even if i would attempt this
since the sunflower is a must in your particular case, i'd put a smaller one on both ends. perhaps inside the innermost part of the scrolls. better balance that way imho. then, there's the desire of the client. they have the cash. i always took seriously, the ideas of a client. if they clashed...
wait a minute, i'm tryin to get my foot outta my mouth ! i assumed the sunfower design was the leek, and not the knife. i learn something new every time i visit the forum.
you asked, so here goes-- the design is quite attractive in its own right. but i think it clashes with the scroll and central panel. the leek would look better in a central panel with scroll on either side. this would exclude the critter, but what is the visual "theme" here ? is the leek more...
you should set it at just a pound or so psi. if insufficient, graduually increase till you get results.
200 psi would likely blow the hoses off the fittings. i don't know about the artisan, but most of the air toys i'm familiar with operate on the cfm rather than the psi.
the lindsay air...
i've used common brasso on nickel silver. and have used lacquer or wax with good results. using lacquer on objects that get handled a lot, sometimes chipping will occur.