When to scrap a W reg Duetto ?

Hoping to have some honest advice here! A little bit of scene setting .  
I love my van. I am 70, pretty fit but not at all handy re repairs. Many plastic parts breaking and use tape etc.  The dog and I probably do 2ooo miles max p a.  It’s a diesel automatic. Has got through mot smoothly so far. In the past the owner had done some replacement work on body panels. Lots of spots of rust. Some under windows and arches and bottom  back doors. No sign of damp. I don’t use water internally. Tanks underneath have lost taps and I couldn’t find anyone to replace . Water I fear is trapped inside. I try to sterilise but I think it is too risky.I could get rid of tanks ? Cheapest option.? Toilet works but I need to use pump and do I need therefore a tank?  Many of you are much more experienced than me. Bristol/ Devon based

We put a lot of money into body repairs on our N Reg Duetto thinking it would last us out and get us a better price when we came to sell it.
We did get a couple of years more use but the trade in price offered wasn’t much more than the cost of the repairs. We both agreed to cut our losses and start again with something that would take us into retirement.
I understand your concern regarding costs but if it’s only a mater of sorting the tanks it might be worth getting a price for repairs rather than parting with it and starting again.

It's a difficult decision, and is very much dependent on the overall condition of the van. That seems to vary a huge amount - often depending on whether the van has spent a lot of its life on the coast, and also on whether it was given any rust treatment early in its life.

It would be worth getting the opinion of a body repair shop, because they should *** be able to give you an honest view about whether the existing rust is surface and/or in limited areas, or whether it is widespread. If the latter, it may be time to let it slip away...

I paid for quite a lot of rust repair work on my old Transit-based conversion (actually a Flair, but very similar to the Duetto) because the rust was bad in only a relatively small number of places. I would not have done that if it was all over the place.

*** here you have to beware the motives of the repair shop, as some will string you along and then "find" extra rust once work has started.