Yes, packages can be wrong... order pickers can screw up. Get a metric thread standard to check your threads, or screw on a known 10 x 1.0 nut; be aware that even1/8" NPT will seem to screw onto it for several threads.
As far as the 'bottoming out' feel, some 10mm pieces may be threaded on a slight taper, not unheard of. Be conservative with the teflon tape, since the bodies of the adapter and sending unit are also providing the 12VDC- source for ground in your circuit. On occasion I've soldered a separate ground lead onto the case of a fat dual sender such as the one you show, just to be sure. Probably a bit anal, but it adds to confidence in the vehicle.
J.R.
SoCal
i installed an electric oil pressure sending unit.
i was told that the thread at the pressure sensor is on the oil filter base is close to 1/8"npt. i ran a 1/8"npt tap into the thread to chase it, just a few turns.
do it a little at a time and test with your new fitting. wrap teflon tape to seal.
i then bought a jegs kit for relocating pressure sending unit. it comes with a 1/8" npt fitting and uses AN fittings in a 3' stainless steel hose.
the electric sender should be remotely mounted to avoid vibration.
i mounted it and used a tee to allow to installation of a 20psi sending unit to plug the OEM wire into for the idiot light.
the 3' stainless steel hose was too long, i later bought a custom length hose with the same ends at 2' long from lubrication specialists.
jon
1/8 ntp is pipe thread.. aka tapers... so screw in till snug and leve it... it works just fine... now 10x1 into 1/8ntp.. no idea if it will seal..
I was just wondering the thread for the oil filter mount sensor. I will be making a custom turbo oil supply line. Ty for the info
I was just wondering the thread for the oil filter mount sensor. I will be making a custom turbo oil supply line. Ty for the info 
i think the oil pressure switch is M10x1.0
and i believe the turbo oil line fittings are M12x1.0, on the REAL TD oil filter flange..
dunno why you couldnt use adapters and such to just go from the M8 on the filter housing to the oil line size..
i dont get it why people call it an oil filter manifold, seen it called that alot in the last month.. a manifold has one inlet, and multiple outlets.. the filter flange doesnt quite fit the definition of a "manifold"
1/8 ntp is pipe thread.. aka tapers... so screw in till snug and leve it... it works just fine... now 10x1 into 1/8ntp.. no idea if it will seal..
They screw in partway and look goofy but it does seal.
1/8npt into 10x1 works fine.
Going the other way and putting a 10-1.0 thread bolt into a 1/8NPT hole "usually" doesn't work. Since the 1/8NPT is tapered the 10-1.0 doesn't have enough thread at the bottom to make a good seal. I have tried in Aluminum and pulled the threads out, might work in steeel, or it might end up going up the threads and leaking around the head. But if you have a copper washer it might seal that too, if the threads are good enough to hold the torque required to smash the washer.
...I'm pretty sure my 1983 Jetta 1.6L turbo (CY) has M12x1.5 threads - straight, not pipe - in the oil filter housing for the oil feed nipple adapter to the turbo oil feed compression line and M10x1.0 threads - again straight, not pipe - for the oil pressure switch on the oil filter housing.
Both oil feeds have copper crush washers too.
...I'm pretty sure my 1983 Jetta 1.6L turbo (CY) has M12x1.5 threads - straight, not pipe - in the oil filter housing for the oil feed nipple adapter to the turbo oil feed compression line and M10x1.0 threads - again straight, not pipe - for the oil pressure switch on the oil filter housing.
Both oil feeds have copper crush washers too.
yes, thats what a factory stock TD should have..
but i believe they are talking about making a N/A filter flange work, and what adapters they would need..