winchester model 61 acting up- circa 1950's|Winchester Research Surveys|Forum|Winchester Collector

Does anyone have a suggestion for a competent gunsmith that works on Winchester model 61 22 cal pump rifles? Mine is acting up- when load magazine, it delivers many shells at once jamming. Installed a new cartridge cutoff. Then when mag is loaded cycles all shells except last one, which remains in chamber, and gun locks up- the trigger lock will not work to release the pump mechanism.

Any suggestions to fix problem? Thanks for looking.