In order to convert it to .308 without rebarreling would involve having the original barrel removed to be rebored. It may not even be possible because your .284 is so close to .308 and if you have any pitting it may not completely clean up. If you are concerned with keeping it original in appearance that gets more expensive because the gunsmith would have to make sure to get the barrel indexed correctly after rechambering. Your most cost effective option is an Adams and Bennett barrel which comes prechambered and requires just a little skilled work from a gunsmith to complete the install.
Certain VZ24 in 7mm mauser can be worth a nice penny. Research what you have before bubba'ing it.