Experienced Joomla developer needed to diagnose and repair broken Smart Slider galleries

We need a developer experienced in legacy Joomla websites to restore broken sliders/galleries on www.uniqstudios.co.uk Multiple pages show: “Smart Slider with ID #7 does NOT EXIST or has NO SLIDES!” “Usage: Used in PHP” Other affected IDs include 128, 32 and 165. The homepage and main photography portfolio are affected: https://www.uniqstudios.co.uk/our-work/quick-photography-portfolio The site has not been maintained for several years. Our developer reports PHP 5.4 and outdated Joomla/extensions. An attempted PHP upgrade caused compatibility problems. Exact installed versions need checking. Our immediate objective is to restore the existing images and galleries while preserving the current design, content and URLs. Scope: 1. Back up the files and database and establish a rollback route. 2. Diagnose the cause, including slider records, publishing status, references, database/errors and recent hosting or extension changes. 3. Test changes on a staging copy before deployment. 4. Restore affected sliders across the site and verify desktop/mobile display, navigation and enquiry forms. 5. Provide a brief explanation of the cause, changes made and any essential follow-up. Please quote a fixed diagnostic fee first, followed by an agreed repair price. Any wider upgrade or rebuild must be quoted separately. If restoring the existing extension is impractical, propose a simple gallery replacement. Our existing developer will coordinate access and technical questions. Please include: * Relevant examples of legacy Joomla repairs. * Your initial diagnostic approach. * Earliest availability and expected turnaround. * Your diagnostic fee and indicative repair range. We are looking for someone who can take ownership and minimise management time.