ya i hear ya from the sounds of it it does work just needs some screws to get it back together and for R12/24 fluid thats the same as any AC charge kit you can get at Canadian tire so if it has the nipple on it you may be in luck
and it should like it does frost up so that means it is running at at least 50% efficient, maybe give him a call and get your hand man side on
my 2 cents