Sonor Snare Head Troubles

Hey guys.

Always come here for help and finally decided to make an account.

Anyway recently i picked up 70's Sonor Rosewood Phonic Snare for next to nothing. Only problem is after measuring the shell size it turns out it is 13 3/4". How do i go about replacing its heads as 14" heads are a little lose for my liking?

Any help appreciated. Thanks in advance

Slightly undersized shells are the industry standard. I'm not well-versed enough to know whether or not 13.75" is within the regular range of Sonor's undersizing but you should be able to put 14" heads on with no problems.