The photo you showed does not resemble a launching v2 size...
That's because the photo showed the wreckage of a V2 rocket engine after it exploded in England.
...so it's things like this, plus fuel and guidance that make maybe's, possibilities and probabilities, then maybe a fact; in time.
What about the several hundred intact V2s and dozens of German rocket scientists and engineers that were recovered by the US and Soviets at the end of the war?
Wreckage after it exploded. Really?
Really.
The first solid lead after the Oklahoma City bombing was the rear axle of the truck bomb, which landed a couple blocks away from the blast. It was very sturdy (it's a truck axle), so it survived the blast. Because it was stamped with a serial number, it was matched to the VIN of the truck, and that was traced to the agency that rented the truck, and then to Mr. McVeigh, who happened to be in jail a few counties away on what seemed, at the time, unrelated charges.
If you doubt the reality of
that event, please track down and interview some survivors and family members of the victims. It was recent enough that there are still a lot of them around. I'm sure they'll be fascinated by your "skepticism".
It turns out that part of the truck's license plate also survived the blast and matched the vehicle identified by the axle. License plates aren't particularly sturdy, but parts can survive an enormous explosion, anyway. Rocket engines are sturdy.
Show me these 100's of intact v2's.
Most of them were, as they say, "expended". Here are some chunks from a couple. These are on display outside the New Mexico Museum of Space History in Alamogordo, NM, USA. There's no charge for the outside exhibit.
Here's one of the few remaining mostly-complete ones. It's at the White Sands Missile Range Museum, also in NM, across the valley maybe 50 miles west of Alamogordo.
V-2 guidance gyroscope.
This museum is just inside the main gate of WSMR, an active USAF base and missile test range. You will need to stop at base security (at the gate) and get a pass to get to the museum. This shouldn't be a problem for US citizens (you may have to prove citizenship - can't remember if proof was needed), but I don't know about foreign nationals. If you're interested, check ahead to see what's required for entry. No charge.
You can look up fuel, more information about the guidance system and stuff on line and in history books if you want. You probably don't.