Slender-Billed Thornbill call

G’day all Just back from a successful lifer hunt for Slender-billed Thornbill in the Little Desert NP, Victoria. For the record I found 3-4 together at -36.531389, 141.650343 a few hundred m east of the Nhill-Harrow Road. I had the Morcombe app with me and familiarised myself with the two calls therein – noting their similarity to the call of the Buff-rumped Thornbill. So over 2 days, whenever I was in the low heath habitat I listened for the calls and several times found Buff-rumps in or near areas with small islands of mallee surrounded by heath. This morning when I caught up with Slender-bills their calls were nothing like those in the Morcombe app but matched those I’ve just listened to from xeno-canto and ibc.lynxeds.com. So my question is: Would those familiar with the Slender-billed Thornbill please advise me if they ever make the calls provided in the Morcombe app – i.e. quite similar to those of the Buff-rumped Thornbills? I realise there are several subspecies and the calls will probably differ. Now to see what HANZAB says. Cheers Steve Clark Hamilton, Victoria