I prepared external artwork of the background inlay for most of the games in the hh_sm510 driver. Get it at:http://tsk-tsk.net/net/temp/extart/
once it's updated.
Except for nupogodi, the G&W games that had internal vector artwork keep the same quality (at width of 4000 pixels). If someone prefers to use the original scans, they can easily make it themself. Nomore final QA decision by me, since multiple artwork sets are possible. The old SVGs are here: http://tsk-tsk.net/net/temp/svg/old/
JR55 and DJ101 have the preliminary vector artwork by RColtrane for now.
Nupogodi has the foreground bitmap from Igor's emulator.
BX301, Tiger & Konami handhelds have the background scans by Sean.