Electrolytic cans that are new are available, however probably not to the exact specs as the original cans. However most likely you can find values that will work perfect in it's place, and look original. I haven't had a lot of luck re-stuffing, and it's quite time taking to do so. I agree it's a lot easier to replace a whole can than in some cases to tack them underneath. Most of the time there is room underneath but in some cases things are so cramped that putting them underneath is almost impossible. Here is a link to a place that has new electrolytic cans hopefully in stock.
https://www.newoldsounds.com/electro...list_limit=all
www.newoldsounds.com