Good. You more than doubled your CCs.
Welcome to the asylum.
The earliest petcocks are not too easy to rebuild, they are the ones called Everbest. They can be worth a few $s because working ones are getting scarce. But it looks like a Karcoma petcock in the pic, can't be sure, too far away. The Karcomas are rebuildable if they only need rubber parts. Some of the other tiny pieces inside the petcock are NLA. We sometimes can come up with used parts.
A complete tool kit is going to cost some serious money and if you want the correct original tool kit the price will keep going up. There are tool kits, used, listed as "original" be careful. There are specific items that belong in the "original" tool kit.
How many miles on bike? Is there any ignition modification or addition? What else non-stock is on the bike?
Start with just changing all the fluids and tune up items. Set the valves. Replace worn or cracked rubber pieces. You will find plenty to do.