Thanks for the comments.
Serial number of the 2x3 is 519780. An inner label lists patents and "Mahoganite (R) Case".
I also have an older 4x5 Pacemaker Speed, ex US Govt, in very good condition, wth serial number 910919.
It has the top illuminated rangefinder
I have not used the 2x3 very much because I use the 6x7 Takumars on the 4x5 Speed and on my home built body.
However I took a test roll of Ektar 100 with the 2x3 and I can see that the Gaftar 103mm lens is really sharp.
The reason I am taking the 2x3 Graflex on the trip is because of the risk that the
home built die cast aluminum camera body might have problems in airport security.
I am only set up to process 120 film ( C41 and b/w) so I use the RH8 & RH10 backs and I have collected a few.
I tend to hand hold the cameras. I set them up on a tripod in the yard with the gg first
and then just use them hand held with the VF.
I have been practising estimation of distances out to about 20 metres, by imagining body lengths out to the subject.
This one with the Takumar 6x7 90mm Leaf Shutter lens.
https://app.box.com/s/s68k5k3nhdcvz07ak2kl
The bubble levels correct my tendency to tilt the camera one way, and also help to minimise camera shake.
Here is a hand held in fairly low light using the 4x5 Speed's rear shutter with the Takumar 55mm and Fuji Pro 160ns.
https://app.box.com/s/zz9woy21e7vmfydsc3ux