Hi,
I have glued 100s of these and use Pattex contact glue (sparingly!). Hot melt is more tricky to keep thin and not squeeze out and then in need of trimming etc.
Since usually one side has a foil lining I find contact glue is the best solution --- just DO NOT put the record back in immediately to prevent the vinyl getting in touch with any out-gassing of the glue's solvent (vinyl does NOT like to get 'gassedÂ’ with thinners :-) I speak from bad experience.
Greetings,
Axel