By Spanish roses I mean roses that were developed or bred in Spain. In particular, older breeds that would have been around 80 to 100 or more years ago.
Starting off with the link, I found that the main rose hybridisers in Spain of the time I was interested in were Pedro Dot and his apprentice Eugenio Fojo, who went on to open his own nursery and create his own roses.
I searched the names of roses provided on https://en.wikipedia.org/wiki/Eugenio_Fojo and https://en.wikipedia.org/wiki/Pedro_Dot_rose_list. I didn't go beyond the first pages of results but it looks like the ones that are said to be extant might be in gardens and not produced for sale, and others seem not to exist any more.
Entering names of roses into .helpmefind.com gave me some more information on the roses (I didn't sign up for the Advanced search), https://garden.org/plants/group/roses/search/ has a long list of boxes to tick for searching. It turns out that one rose can have different names. For example, the rose I decided on with the original name of Irene Churruca (bred by Eugenio Fojo, Spain, 1934) is now also called Golden Melody. A result also brought up Encyclopedia of Rose Science at books.google.co.uk with details of roses.
I had emailed a couple of Spanish websites and didn't receive replies (perhaps because I used Google translate :/ ). I also emailed a UK rose specialist but I think they misunderstood my request, twice, so I didn't bother again. I later saw that they did sell some, but they said "we only sell roses produced in the UK", they didn't stop to think about my enquiry. Those were general requests about old roses bred in Spain. When I searched for the name Golden Melody, the result of a UK supplier came up. It turns out they're the only suppier in the UK of that rose, but it was just a bit too late to get one and now I have to wait until November. I found the Para Ti patio rose (Spain 1946) (there arevarious other names for this one) on a website that I'll have to contact for a price - it might be a small independent nursery.
Not that I'd order from abroad, but a German site looks to be selling one of the oldest roses from Spain, (Francisco Curbera 1923), it doesn't give prices, just an invitation to send an enquiry so this might mean they don't sell all the roses they advertise. It would be interesting though if roses created from that far back were still being sold.