Diesel fuel is a simple mixture with the following ingredients:
Ether*
Kerosene**
Oil***
Dope**** amyl nitate, amyl nitrite, hexyl nitrate, isopropyl nitrate are suitable.
*Ether is used in the range of 20-30% by volume and its SOLE purpose is to lower the self ignition temperature (SIT) of the fuel mix to facilitate starting.
**Kerosene is used in the range of 33-50% by volume and it is this that gives the fuel mix its energy of combustion.
***Oil is used at 20-33% by volume and lubricates the engine. You can use virgin extra pressed castor oil or synthetic oil containing about 10% castor.
****Dope is used at 1-2% by volume and this can help in promoting smoother running or extracting more power in the case of racing engines.
I mix my own fuel and my basic recipe is 25% ether, 43.5% kerosene, 30% oil and 1.5% amyl nitrate.
Only mix as much as you need for a week or two, typically 100-250mL and keep in a well sealed container and protect from direct light.
If you do have access to ether, keep no more than 500mL in your workshop or wherever you do your modelling. It is very volatile and seriously explosive when in vapour form. Flash point is -35C and 4% vapour in air will cause a big bang if ignited.
I am an experienced "diesel head" and have learnt what I have written over a long time.
Enjoy your diesels and have patience with them especially if you are starting out.