I have a 3cyl diesel Super Dexta; I've always thought it's a 1954. On rt side trans case is "ENFO 957E7005, T3, 4B20. On rt side clutch housing just below starter 4C10 T4 957E7505C. To start key must be on and press down on starter engage lever. I have a parts list for 57-64 models. I have intermittent trouble in that sometimes press down on lever & nothing happens. I think it may be that the starter relay switch does not make contact. In my parts book this switch is pt no ED1ADDN-11500. Looking at this switch in parts list on this site is E1ADDN11450C, but the picture of the switch is significantly different than what's on my starter, however the parts on this site say they're for model years 61 thru 64. I suspect that inside the starter relay switch there's a brass or copper disc to which electrical contact is made when the lever is pressed down, and that this disc is corroded or carboned up so contact may not always occur, and that if I access this disc and clean it up the problem will be corrected. Any comments will be much appreciated, & Thanks!