That is correct that the US sold VX didn't commenly have a v-tec labled valve cover, but they do have a distinctive valve cover, the oil fill hole is on the drivers side, twards the rear of the valve cover, and the spark plugs are along the front, base modle civic engine has spark plugs twards the rear of the valve cover, of course the vx, and the si share a valve cover gasket, and I'm not sure how their valve covers differ, so really, an engene bay photo will help alot, as would the door lable that gives tire size and presure (165/70 tires are vx).
Look for EH237 in the vin.
Also a 5 wire O2, only the VX uses the wideband O2.
Passenger side of the valve cover at the rear will have a solenoid and oil pressure switch. This is Vtec. If that's not there then it's not a VX engine.
The VX will also have a tach since it's a Vtec motor. This car is most likely a CX with a D15B7.