I can see where your coming from but if there is no identification then there is no V5 to obtain.
Unless you are able to identify the chassis VIN number and track the V5 that way you will need a IVA.
If you have no V5 you have no route to obtain the tax disk.
At 99p its worth the risk of having to pass an IVA, nice completed one in Black on currently as well.
Not sure the top mount of the front suspension is 'man enough' for the British pot hole.