Does the album say that Namiki composed for RAIL CHASE? I see there's a lot of sites that say he composed for it, but nothing that I would consider source-worthy. I bring this up because I found some
random Japanese site that says, 3 times no less, that Keisuke Tsukahara composed for it. Also, Kazuhiko Nagai's page on SEGA RETRO has the game listed in his production credits, though I'm guessing that was added purely because his photo is from the
announcement page for both Rad Mobile ORIGINAL SOUNDTRACK and RAIL CHASE ORIGINAL SOUNDTRACK, which isn't really evidence for it. Even so, I don't know any sources that back up any of these 3 claims.
EDIT: So it seems Rail Chase is listed in Tsukahara's works in the booklet to GALAXY FORCE II & THUNDER BLADE ORIGINAL SOUND TRACK, so at least his involvement is confirmed. Still don't know about Namiki.
EDIT 2:
Now I know the source. Of course, this doesn't confirm his as composer, it could be for some other element of sound.