Try contacting
H. Lloyd Cycles. I doubt they'll do those ones 'off the shelf' as I can't imagine there's much market for them, but they might be able to knock them up for you.
Alternatively try some local sign makers, the sort that do vinyl sticker van signage. I've had stickers made by a guy who does this in the past.
Or better still, remove the decals all together, stealth is best
