You can see if the spring is broken just by looking. Simply take the stock off.
Enfields are fairly easy to work on. Replacing the sear spring isn't difficult. Takes needle nosed pliers and a screw driver.
The old Surplus Rifles disassemble/assembly How-to is here.
https://www.dropbox.com/sh/kh9guf4wv...MKJajVKra?dl=0
Exploded No. 4 Rifle drawing is here. http://stevespages.com/ipb-leeenfield-no4.html
$6.45 each for a used, "condition may vary" sear spring from Gunparts. Listed for who knows why under 'SMLE'. A No. 4 is not an SMLE.
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