Hunting missing Bitcoin from Multibit Classic I've spent days trying tons of things but hope someone can give a bit of direction.

So I purchased bitcoins, only a few in 2010, early. Then end of the year I imported them in to Multibit Classic 0.5.15. Thought great way to save it and deleted the old files I created with original purchase. Coins showed in the wallet. Then in 2013 I checked again and they where there, thought great. So I switched to SSD on my laptop and kept original hard drive as is.

I've now managed to get it back in the laptop, get the wallet files but low and behold balance 0 and I cannot see the imported key for the coins.

I've updated to Multibit Classic 0.5.19, synced around 7 times and still nothing.

Should the private key for importing the coins show in the wallet? So if I go export keys it should have two keys? Or is the wallet the only key that will be exported and I can import that in to Bitcoin Core even though the imported key is not showing in the export and the keys, bitcoin address, history nor are my coin balances are showing in the wallet? I had 0 transactions. Just imported, checked how many I have and value and left it only with install and again before changing HDD did I check and it then showed the balance. Will the keys only show after update or should they already show? 

Any and all help appreciated.
Should the private key for importing the coins show in the wallet? 


Most wallets will not show you the private keys unless you explicitly request them in the menu. This is for security, because the private keys are all you need to spend the coins sent to the corresponding address, so they should be kept as secure as possible.


  So if I go export keys it should have two keys? Or is the wallet the only key that will be exported


Your wallet can have multiple private keys in it, usually one private key per address (at least for addresses starting with a 1). So the number of keys exported will just be the number of keys in your wallet. Your bitcoins will have been sent to one or a few of these addresses, other addresses might have no coins sent to them. 


  and I can import that in to Bitcoin Core even though the imported key is not showing in the export and the keys, bitcoin address, history nor are my coin balances are showing in the wallet? 


Yes, the keys are all you need in order to import the addresses into another wallet program like Bitcoin Core. The wallet will then calculate the corresponding address, and look through the blockchain for transactions sent to that address (as long as you import with the rescan option set to true).


  I had 0 transactions. Just imported, checked how many I have and value and left it only with install and again before changing HDD did I check and it then showed the balance.


What do you mean you had 0 transactions? In order to have any coins, they must be part of some transactions. Do you mean no transactions are displayed now, but they were earlier?