I'm finally installing the seatbelts supplied with the 320 kit many years ago.  This is the standard Y-piece anchored on the hat shelf and a lap belt. Problem is that the lap belt only has a length adjustment on one side and, after adjusting it to fit, the buckle where the two shoulder belts attach is way off center.  It seems like an easy alteration to shorten and add an adjuster to the fixed half of the belt.  Any recommendations on where to get this done?  A shop in the Houston are would be most convenient.

Thanks in advance,
Chris.