https://smile.amazon.com/gp/product/B07RJR1XPH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I'm using this though its not ideal, needs recharging several times a week. i hadn't though of using old laptop speakers, i'll do some ebay and amazon searching.
Do you need to retrieve the record later? You could encase it in epoxy while it's lying on the picture frame glass. Otherwise get 2 matching picture frames and affix them back to back.
For the MP3 player there are some low cost ones like Sandisk and Agtek that would fit the bill perfectly. External phone speakers of some sort could plug in directly.