I've got a spare 21.1 stem ,I drilled and filed it, currently polishing it. It looks good with a set of randonneur or moustache bars but looks like crap with drops... heres a crappy pic if interested get in touch
edit...You might want search for 21.1 BMX stems there are some cool and cheap ones out there for a more modern "trick" bike look e.g. http://www.winstanleysbikes.co.uk/product/33788/DiamondBack_Quill_Stem or look for stems for Schwinn Cruisers, I'm pretty sure they were all 21.1mm back in the day. Kalloy also make one in black that looks more "normal" but they only came in a 15 or 20 degree rise if I remember correctly Just found this one that looks pretty interesting but for bmx sized bars http://www.ebay.co.uk/itm/YO-Unique-Super-Chunky-Schwinn-YO-Old-School-21-1-BMX-Handlebar-Stem-/300667689479?pt=Cycling_Parts_Accessories&hash=item460130da07
@Jay75 started
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I've got a spare 21.1 stem ,I drilled and filed it, currently polishing it. It looks good with a set of randonneur or moustache bars but looks like crap with drops...

heres a crappy pic
if interested get in touch
edit...You might want search for 21.1 BMX stems there are some cool and cheap ones out there for a more modern "trick" bike look e.g. http://www.winstanleysbikes.co.uk/product/33788/DiamondBack_Quill_Stem
or look for stems for Schwinn Cruisers, I'm pretty sure they were all 21.1mm back in the day.
Kalloy also make one in black that looks more "normal" but they only came in a 15 or 20 degree rise if I remember correctly
Just found this one that looks pretty interesting but for bmx sized bars http://www.ebay.co.uk/itm/YO-Unique-Super-Chunky-Schwinn-YO-Old-School-21-1-BMX-Handlebar-Stem-/300667689479?pt=Cycling_Parts_Accessories&hash=item460130da07