1/8 BSPT adapter for oil pressure sensor

[Dino86]

So, I bought a oil pressure switch from an AE92 to fit Oil-P warning light. It's also 1/8BSPT as the original sensor in the AE86.

Since I want to keep the original sensor also,I wanted to buy a T piece with 1x male 2x female 1/8 bspt.
But it seems impossible to find it.
Anyone knows where to buy it?

Or,
- Can I fit 1/8 BSP onto BSPT? Is the thread in the Engine BSP or BSPT? I could find Y piece with 3x 1/8 BSP.
- Many T pieces are 1/8BSPT male and 1/8BSP + 1/8 NPT female.
But than I can not find a adapter from 1/8NPT to 1/8 BSPT.

Any help/advice is welcome.

Thanks already.