> does your bus have a "1500"
> chrome emblem on the back engine lid?  or on the space between the engine
lid
> and rear hatch?

No.
 - -- - - -
could it have fallen off - are there holes?

> 0 301 353 -  ~ early sept 63
> 
> 0 590 821 -  ~ early june 64
> 
> what is your chassis number?

1165853   (Sept. '63 is on the plate)
- - -
yes - sept  63, sounds like 0 301 353 was the original motor. 

> hope this helps

It sure does!  So, if the leading zero is the seventh (or first) digit, 
then this motor is (and the original was) a 40 HP?  I thought that the 
'64 USA imports were 1500 standard?

   i am counting the first 0 as a null digit, and would assume it came with a
1500.    
64s came with the heavier duty front suspension and larger brakes.    From
jan 63 through end of 67 buses could have come with a 40hp or a 1500 motor.
 but i think you are right in saying 1500 is standard for a USA  '64.

clara