oil sending unit mod

[61Alpine]

I'm installing a 3tc/t50 in a 61 Sunbeam Alpine. A problem I ran into is finding a fitting to replace the oil sending unit. The Alpine has a direct line oil pressure gauge.
I took the sending unit to several auto & hardware stores to be told the threads are m10 - 1, 1/8 npt, and 1/8 mnpt. Tried all & none work, They only go in 1/2 of one turn & tighten. The sending unit goes in about 4 turns easily before tightening, so the block threads aren't cross threaded.

Anyone know the thread size or fitting to replace the sending unit

Converting a Sunbeam into a Toybeam

[Estebot]

I have a braided line in mine made by hose and fitting. Amazing nice piece and cheap? Make it right in front of you in whatever ends, hose material and length you need.

http://www.hoseandfittingsetc.com/

See if one is near you. If not a similar place.
I also have an adapter from metric to npt. I think from earls?