@Poppy78 The simple answer is yes, but how much it's going to cost will depend on your property, when you wanted it doing and who you get to do it - can run into the hundreds of pounds. There are a lot of independent firms who supply and fit gas and electric meters and if you engage one of them they'll liaise with SP on your behalf to get it registered and confirm new opening reads. The benefit of using an independent firm is that you'll get it done to your spec and timescale. If you ask SP to do it, they'll 'negotiate' a price and timescale with you and it might not fit in with your building schedule.
Remember, you do not have to have a smart meter, but any new meter fitted will almost certainly be digital as I do not think they make the old dial analogue ones any more. SP should be able to supply you with one of these if you ask, but of course, you'll have to pay for it, and knowing SP, a couple days after they've fitted it, you'll start getting asked if you want a smart-meter fitted, 'at no extra cost'
TBH I would go down the route of seeing if SP can adjust your existing Eco7 meter to a single rate and change your tariff accordingly. Some meters can be altered this way and it would save a lot of hassle and cost if yours could.
A third alternative is to see which suppliers CAN adjust your meter and tariff, and switch to them. Some used to be able to do as simple a thing as combine the two Eco7 readings, but that doesn’t necessarily mean it would result in a cost-effective tariff.