Are my tomato plants salvegable?

Hello, I'm quite new to gardening and could do with some help with my four very sad tomato plants.

I bought them from a stall run by a local allotment society. I don't know what variety but they are bush rather climbing types.

I have them in a window box, that moves outside when it's sunny and is inside when it's not, as I don't have a greenhouse and the cover blew off my cheap wilkos cold frame thing.

They were doing quite well until a couple of weeks ago. I first noticed aphids and little white flies on them and brushed them off. The aphids are all gone now. They may have got left outside in the rain and wind once or twice..

Now they are very droopy, the leaves on the lower branches have first curled then turned brown and wilted. I notice what look like blisters about three quarters up the main stem.

Here is a picture. Are they too far gone? Is all this inside/outside killing them?

 

If you do feed them, only use a feed that is low in Nitrogen BUT high in Potash. Nitrogen encourages too much leaf growth, potash gets them flowering, then fruiting. Try and give them a sunny spot. Think of that lovely taste of your own tomatoes in a couple of months,

 

Thanks! I haven't fed them at all, couple of flower buds but no fruit yet. There is also damage on the upper leaves where it looks like the leaf has thinned: internet search suggests stress/they got too wet/ or it's a virus and they're dead plants walking.

It's occurred to me it might be doing something else they might not like as I put four in one large window box. Reading around it seems like this is might be too crowded for them. The allotment people thought I would be ok growing them in containers/ windowsill, so they can't be a variety that's huge.

Now I'm thinking, should I split them and have two to a window box. But at this stage - they're probably 50cm high, would that do more harm and should I just let them be?

 

Reet good,
there is a Tomato Growing 2012 thread that relates many, many problems that us toms growers' encounter during the season. You won't feel so disheartened once youv'e had a look I think,
Jenny namaste

 

Cheers, I'll have a look! I know they're not the easiest, but I would like to hope it wasn't me hastening their demise...