[Proj] Saudi 1:50000 maps & grid

[Irwin Scollar]

For a remote sensing project using Google Earth imagery on the border 
with Jordan, I need to know the scheme used for numbering the 1:50000 
Saudi  maps on the other side of the border. I have searched in many 
places on the Internet and found little data of help.

I also need to know if the UTM grid based on the International 1924 
ellipsoid also appears on these maps in addition to Ain el Abd datum 
latitudes and longitudes.

The NGIA 3 parameter transform constants to and from WGS84 from 1991 
at 9 stations is rather outdated.  Are there 7 or 12 
parameter  transform coefficients available anywhere?

A brief explanation or Internet links will be greatly appreciated.

Irwin Scollar