I think if you added up all the new bits you'd need when you find fixings, brackets, clips etc are also corrded and fail when you remove them . . . add costs for such things as new brake pipes, their fittings and clips, hoses as well, fuel lines . . fuel tank? Are you going to reuse all the old rusty bolts . . . old nuts . . . cost of those adds up. And if you are rebuilding the chassis, it makes no sense to hang axles you haven't at least given a good coat of looking at on old bushes, with old springs/shocks . . .
Unless you have some emotional attachment, you might find from a purely financial thinking about it while thinking the money is better in the mortgage, it makes more sense to get another few years from another couple of MOT bodge-ups, then weight it in/leave it on bricks in the garden while you spend too long flogging bits of it on ebay/leave it where it is until you really do have several grand more than you think you need spare.
Unless you have some emotional attachment, you might find from a purely financial thinking about it while thinking the money is better in the mortgage, it makes more sense to get another few years from another couple of MOT bodge-ups, then weight it in/leave it on bricks in the garden while you spend too long flogging bits of it on ebay/leave it where it is until you really do have several grand more than you think you need spare.