Help me identify this calculator?

[cautiousone]

So I picked up this calculator from an estate sale, I've seen lots of HP calculators in the past, but never seen one locked up in a case like this. Since it is locked up tight and no key was found I'm stumped as to what calculator it's housing. Any help would be great and thanks in advance. Damon

Edited: 21 Feb 2013, 2:54 p.m.

[Monte Dalrymple]

HP-21

[Thomas Klemm]

HP-21

Cheers

Thomas

[cautiousone]

Thanks for the help.

[Frank Boehm (Germany)]

Oh, and something to add. That lock is pretty hard to lockpick - the usual way is to crack open the case.

[aurelio]

That is my calculator!!!!!! =:)

No, this is mine

and this is the older "sister"

If you have not the key, go sure to a locksmith for assistance.
good luck

Cheers

Edited: 21 Feb 2013, 5:46 p.m.