another Question on the VAIW { pic }

after cleaning parts up for painting , I notice some parts stamp with " EXV- a number " ...wondering does "EXV" MEAN anything ???

found a VAB124-20135 on engine kind of behind oil filter .. Does that mean anything ... { there's no serial plate , trying to figure out what year my tug is ..

ONE other thing ... on rear axle on back side found a plate attach by 2 screws ... it had these numbers ...
... 6 - 4 - 51 ....
DO you think it might have been built June 4 , 1951 ??

THANKS again for ANY information ............... mark

EXV casting number prefixes are for experimental parts.This means your tractor has experimental parts on it. Since it was used in the factory it is hard to say at this point if it is an Experimental tractor or was put together using up experimental parts. If you could post a picture of the tag with 6-4-51 and of the casting numbers with EXV I may be able to tell you more.Your tractor is at the least a very unique unit. The VAB124-20135 is the engine serial number. The engines were built in batches with their own serial numbers and were installed in the tractors in no particular order,just what was convenient. I have a 1944 VAC with engine serial number VAB124-18614.That means our engines were built about 1500 apart. Your engine was probably built within months of my engine as over 7000 VA series built in 1944. I have been told that there were extra VAC engines everywhere at the Rock Island plant. So if your tractor was built in 1951 they could have used a left over engine and could have used an engine that was rejected by quality control for some reason such as a casting flaw. Please post more pics when you can. Nick