Looking for a replacement carb for a Tecumseh V50-60077e engine. Looks like someone replaced the carb from a newer engine. The online parts lookup places list carb 631799a as the replacement but there are a lot of parts you can't get. Looks like carb 631101 was the original carb and you can still get most of the parts but there are no service carbs available. Could you buy carb 631799a or even 631800a and use parts from 631101? Also what parts do you have to buy when you get a service carb?