540 / 1000 pto GD and Paint color

The production code on my '69 5000 says that it is a code 6...540/1000 GD as opposed to a code 5...540/1000. What does the GD stand for? Service manual list the code but does not explain. We pressure washed it today prepping for a complete overhaul and found that the original color was white! the entire tractor has Primer then white, then green and finally Empire Blue. Probably for a gov't agency but I didn't know Ford made them in custom colors. Thanks guys, you have been a great help during this adventure.

I'm no SOS man but wasn't there a GrounD speed option on some of those?
Maybe that's what it means.

No SOS, it's an 8 speed. Complete number is E1016C.

Oops.
I'd better let the others take over from here.
I'm not rear familiar with anything over 4000 size.

The production code is a code for the date that the tractor was assembled. The number you have posted is the model number.

The 6 in the 5th spot in the model number is the designator for Independent PTO with 540 rpm, and 1000 rpm and Ground Speed. I am pretty sure that all 5000 models had that available no matter what transmission, as all of them, even the S-O-S models had the same independent PTO in the rear axle like the non-S-O-S 4000's had. The 3 cylinder 4000's, on the other hand, only had the ground speed PTO available on the S-O-S models, which seems kind of backwards when compared to the 5000's.

You should have one lever near your left toe as you sit on the tractor that has three positions, one is 540 rpm, the middle is Neutral and the third position is 1000 rpm. There should be another lever further back, near your left heel when you're sitting on the tractor, and that one is for the Ground Speed. The Ground Speed lever has two positions, disengaged and engaged. You can only move the Ground Speed lever to the engaged position when the front lever is in its Neutral position, and you can only move the front lever out of Neutral and into either the 540 or 1000 rpm positions when the Ground Speed lever is in the disengaged position.

The vast majority of 5000's were 540 PTO only. 1000 / 540 Two Speed PTO parts are listed as beginning 1/1/1973 which is concurrent with the introduction of the Dual Power option. Nothing I can find in the parts catalog indicates a ground speed PTO option for a 5000 or 1000 RPM PTO before 1973. Less importantly, I have never seen or heard of such equipment on a 5000.

Sorry about the production code vs. model thing. We were looking everything up and I just typed the wrong name....brain fart. Any thoughts or ideas about the paint? The only thing that seems to have been blue from the beginning is the fuel tank which may have been replaced. Did Ford paint them special for larger orders?

I could have sworn that I had a reference showing the dual speed plus ground speed transmission on a 5000, but I've looked through everything I have and I can't seem to find it. But the model number on this tractor is E1016C, so that would indicate that it has it, unless somebody stamped the wrong number on the flat spot.