Vacuum the loose stuff out of the intake, pull the R/W impeller, open the decompression lever(s) if you have them, hold the fuel pump
in no fuel
mode, and spin it over until you see oil
pressure. When that happens, close the decompression, allow fuel
to the engine and see what happens.
If it fires or starts, shut it down, reinstall the impeller, open the R/W supply and start it again. Small diesels can be very forgiving indeed...
I'm assuming you've checked that you have clean fuel and filters...