We have a Harrington & Richardson Model 900 (.22 2.5" bbl)... It's been in storage 40 some odd years. The gun appears seldom if ever fired, but the plastic trigger spring bushing has fallen apart. We've ordered a replacement from Numrich w/steel steel bushing instead of plastic. It should arrive in a week or so.
The photo shows one side of the bushing extending on the same axis as the spring guide, and the other side diverging from the axis of the spring guide at about 30 degrees. This forms a "cup" into which the hammer fits.
The mainspring is inserted with the bushing at the trigger end, but I don't know if the offset should angle toward the top of the trigger or down toward the trigger hinge. The plastic bushing was in too many pieces to determine its orientation before it fell apart. No response on the technical forum yet.
The Numrich site shows a good photo of the part, with the offset bushing.
Thanks in advance for any info!