BSPP Fittings 1/8 inch stainless steel

Hello to all. Just getting into pcp rifles. A friend passed away and I received his things. Airventury Avenger, Young Heng compressor and other items. It has only been used maybe five times. Anyway my question is, does anyone have a good source for the BSPP 1/8 inch fittings? Looking for a couple 90 degree. I seen the price for the delrin gaskets they are ridiculous. I have a miniature lath so will order a delrin rod and turn my own. Can you use regular o-rings in place of the delrin gaskets? All help is appreciated. Thanks Wayne
 
for seals

fittings

for seals

fittings
 
On fittings all they show is BSP. What is differance between those and BSPP?
for seals

fittings
On Fittings all they show is BSP. What is differance between BSP and BSPP?