Yes, it could be, it has the same characteristics - sepals and buff stamens.

Could it be Rebecca?.... I bought one recently for a more shaded area and it is blooming beautifully

Bit too early for it to be Ernest Markham, that's a viticella group one - trouble is, there are so many varieties now, but this looks like one that has large flowers May and June and smaller flowers around September. Something like Barbara Dibley? That's petunia red and has eight sepals, though if you look on line, you could be forgiven for thinking its pink...

Thanks for replies. Flowers are 5-6 inches diameter. Plenty more buds waiting to open too. There are also 3 more clematis around, without labels thriving and waiting to flower. Quite exciting to see how they'll look... :-)