Help
Scoring: MP
Quantumcat would have got this right at the table (except hearts were 4-3 and not 5-2 as you assumed). West did have 3 points (CK) as you guessed, and if you play diamonds the way you stated, you will make 3 diamond tricks + you can use the dummy entry to play clubs. If you were at the table, the play to various tricks till then would help you know that hearts were 4-3 -- enabling you to avoid playing a third round of spades and preferring to play clubs. (If at the table, you'd ask if 1NT can be with 5-card major)
kenrexford would probably go down in this contract. The play in clubs at trick 6 creates the setting for an eventual club winner but defense makes 5 tricks before you make 9. Either opponent (I'd guess West) wins the club and returns a third heart. Now you have 3 diamonds, 2 spades, 3 hearts and can set up a club winner. Unfortunately, opponents have an established heart, SK, CA plus the 2 tricks lost (CK, DJ).
vuroth, in his first post, said "leading the SJ will do". I think this is probably the best thing to do at trick 2 as long as you do not repeat the spade finesse if it wins. If East wins the SK at trick 2, you have 3 entries to dummy and should be able to use them to make your contract easily!
nigel_k's points are valid. This is a deal where being at the table (e.g. to ask opps about their run-outs, or if 5-card major is possible in 1NT) makes a big difference.
I played for 3-3 in spades (tricks 2-3-4 were S to A, S to J and Sx from hand) and then lost my way fairly quickly to go down. This was the last deal of the day and I have noticed I play worse than my usual poor standard on the first and last deals of every club session.
Please feel free to comment / criticize.