The $35k US example you posted is probably not a good price guide as if you look at the photos closely it has evidently not been restored, just tarted up and blown over. This may have been done as a museum exhibit or it may have been done for sale. Either way, it isn't as good as it appears at first glance and it's in the US; it's likely Axis vehicles would fetch more over there than in Europe as they'll be less common.
In any case, you can't assume a general restored value from one or two examples.
To be honest, I can't help feeling the value of something like this is likely to be 'what you can get for it', which may be a lot or a little depending on who's in the market.
You probably should not reckon on making a fortune on it, or buy it with the sole aim of doing so; there are very few vehicles that repay their restoration costs and turn a profit.
Really, when valuing vehicles, there are a few ways
- what will it make restored, less the restoration cost (difficult to know as not enough are sold);
- what is the open market or book value (see above);
- what is it worth in scrap or in breaking value;
- what is it worth to you;
- what does the seller want.
If several of these tally, you know you're about right. If you have no idea about any of them, it comes down to how much you want it! If you do really want it and are interested for more than a quick profit then the answer to what it is worth is how much can you reasonably afford to pay for it without stretching yourself.