Check out these machining calculator images:
Wilhelm Schickard machine replica 1623
Image by teclasorg
Vintage 1975 CBM calculator in original box!
Image by Gerard van Schip
I know, not spring however but spring cleaning is here, verify it out on eBay:
cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=S…
Adding machine
Image by bcostin