ATM Advice w/ specs on 12.5" Newt

[BodyByJay@aol.com]

I just purchased a JMI 2" NGF-DX2 focuser for the 12.5" Newt I am building.
Apparently the racked in height is 1.85" (including .25" base and 0.10"
plate).  When fully racked in about 1.1" of draw tube extends into the OTA.
The fully racked out height is about 3.0".  

The draw tube, when fully racked in protrudes into the light cone .25".  I
determined this by taking the ID of the OTA of 15.4 and subtracting the front
aperature diameter of 13.7" to get a space of 1.7".  Half of 1.7" is .85" and
so that is the space between the OTA inside wall and the light cone.  The
focuser protrudes to about 1.1" so the draw tube can come into the light cone
when fully racked-in by .25".   Is this bad?  

Here are the specs I get from NEWT 2.5, would you mind please looking them
over and commenting.  I would like to know what you think and maybe you have
some ideas for improvement.  I am especially concerned about the diameter of
the 100% illumination focal point.


Optical diameter of primary:                            12.3 (12.5")
Optical diameter of diagonal minor axis:        2.12 (2.14")
Focal ratio:                                                                    f/5.309
Focal lenght:                                                                   65.3"
Tube I.D.:                                                                              
15.4"
Tube wall thickness:                                                    0.30"
Focuser to tube front:                                          21.5"
Mirror face to back of tube:                                    6.2"
Focuser height:                                                         1.85"   (racked 
in)
Spare focuser in-travel:                                                .75"
Additional height for camera:                           0               (visual only)
Focuser inside diameter:                                                2.0"
Diagonal offset:                                                                0.10"
100% Illumination Diameter:                                     0.1694"
75% Illumination Diameter:                                      1.2099"
Front aperature diameter:                                       13.695"
Mirror face to focuser hole:                                    54.8"
Focuser to front end:                                           21.5"    (light shield)
Mirror face to back of tube:                                    6.2"
Tube length:                                                                    82.5"

Any comments or advice would be much appreciated.

Thanks,  Jay D. Anderson