Its a Henri De Rivel isnt it!? Rode in one last year, the quality was shocking, really didnt like it....but the old ones are lovely....difficult without seeing and being able to feel the leather.....
Best single flap ones IMO are the Ideal saddles or the Exselle single flap. Both nice leather and good trees for the horses back. CAn recommend a very good saddler in Bury St Edmunds that travels good distances if he is anywhere near you!? Sorry geography is crap....
If you like that sort of design the Jeffries flyover might be suitable. My saddler was willing to do a deal which made it about £900. I prefered a prestige though.