Brake Fan,
Thanks for the geography lesson on the B707. The grating to access lower 41 is indeed behind Capt seat. To open it you needed to be a few clicks fwd on the Capt seat so the obs seat could be tilted fwd to clear the grating as it was lifted to open. This grating is under the fwd end of the Nav table.
About the NLG pins on the B707. There are 2 used. The 1 I described is the only 1 you would dare use for towing coz it physically fits into both sides of the knuckle on the oleo brace and prevents any movement towards retraction. Because the pin fits through the brace knuckle it is towards the top of the NLG well and hence quite a way from the ground, a couple of metres at least. Enter the bicycle handle on the opposite end of the long rod from the actual pin so you have control over it to guide the pin into the knuckle. The handle bar bit rested on the cover of the NLG steering actuators and was an excellent place from which to hang your red flag. The other, I think alluded to by the story, is a little bayonet T handle inserted on the left side of the NLG on the skin of the a/c about half way along the NLG cutout as I recall it. I also recall that it loads up the knuckle to prevent movement in the retract direction. Most unreliable bit of kit. The T handle was only used for static loads like parking and was simply unsafe for towing. Been a long time.
As for reaching the bayonet T handle from the lower 41 external hatch, forget it. Way too far.