-It would probably weigh in the 10,000 lb range.-
5Kt vs 20 Kt. As a moron, I will accept that your value is closer.
-I have worked on the engineering on two intermediate range nuclear missile programs.-
Hmm, the W69 and W80 warheads maybe?
No. One was W-50 and the other was W85 and W86, but the W-86 variant was cancelled (low yield earth penetrator viewed as too easy to use and could cause nuclear escalation)