I was keeping any eye on preloved, friday-ads, new rider, equineadverts and freeads. As it is, I found a fab thorowgood GP on freeads for £70, almost new condition and perfect for my boy
I know the feeling, I put up wanted ads on all of those sites as it was free and it definitely generated a lot of leads. In the end I replied to someone else's add but it's always another way of letting people know what you're after
instead of websites, if you try your local saddler, they often have a selection of 2nd hand saddles for you to choose from...and they will fit them to your horse xx