I've a number of slide rules, abacuses and calculators of varying ages and condition. I am beginning to concentrate my efforts on Special-Purpose slide rules: the more obscure the better.
Don't expect to find much more at these links than images. I've only bothered to comment on a few of them. If you're really interested and want more details I'm sure you'll contact me.
Slide Rules
Aristo Scholar 0903LL, Scholar 0903, Scholar LL 0905, TriLog 0908
Concise 28N Circular, 300 Circular
Faber-Castell 'Statics', 367, Novo Duplex, Darmstadt 1/54, 57/22
Fuller Fuller Cylindrical by Stanley, 1941 Griffin 121 Halden Halden's Calculex Sun-Hemmi 30 (pre WWII), 30 (post WWII), 40RK, 50, 64, 80K, 101 4' Teaching Rule, 130, 135, 149A, 257, 259D, 80/2|3, P261, Unnumbered (Pat.51788)
Hope 53
Keuffel & Esser K-12 Prep.
Otis King's Pocket/Patent Calculators A7942 A9123, A0666
PIC VP124
Pickett Microline 120, 160
Relay 55
Ricoh 252
ROOS SR104
S100 Universal Circle Slide Rule Unique LOG-LOG, Universal Slide Rule U1
White & Gillespie DualFace 432, DualFace 432 (with thumbwheel)
Andy Kinsman's Postscript Slide Rule (in PDF)
Charles Kankeborg's Postscript Circular Slide Rule 1 of 2 (in PDF)
Charles Kankeborg's Postscript Circular Slide Rule 2 of 2 (in PDF)
Flight Computers
CITIZEN Wingman VI Flight Chronograph
Dalton Dead Reckoning Computer
Felsenthal & Sons Dead Reckoning Computer
Sanderson Flight Computer
Telex Communications Inc.
White & Gillespie Navigational Computer (RAAF)
Specialist Slide Rules
Alcott Steel Weight Finder
Capitol Savings & Loan Perpetual Money Plan Calculator
Andrew Antenna and Propagation Computer
Andrew Parabolic Antenna System Computer, 1957
Andrew Parabolic Antenna System Computer, 1964
Andrew Transmission Line Computer
BioMate
Blackwell Calculator
Althouse Chemical Co., Inc.
Fearns & Mear Costing and Estimating Calculator
IRI Infrared Slide Rule
Kaiser Aluminium Weight and Footage Calculator
Kennametal Calculator (1949)
Kennametal Cutting Speed Calculator (1949)
Marconi Signal Source Calculator
Motorcraft Gasculator
National Standard Company Strip Calculator
Proportion Wheel
Radiac No.1
Raytheon Radar Performance Calculator
Readymix Concrete Calculator
Repco Ergometer
Republic Steel - Sheet Weight Calculator
Rowe Coil Weight Calculator
Scalextric Speed Computer
Shure Reactance Slide Rule
Transpos-a-Chord
TwinDisc Metric Equivalentor
Wean Equipment Corporation - Gauge and Weight Calculator
Wean Engineering Company - Gauge and Weight Calculator
Weathercaster
White & Gillespie Proportion Calculator
Sliding Tables
Beer Styles of the World
101 Cocktails Calculator
Automotive Fault-Location Disc
Blundell Harling Metriverter
Concrete & Lumber Calculator
The "Dandie" Cocktail Slide Rule
Derck's Gauge Dial
The Great Australian Distance Computer
Paint Gallonage Computor
Golf Coach
Lufkin Screw Thread Converter
McDowell's Perpetual Calendar
Medical Slyd-Rul
Pix Newspaper "Rite-Change" Calculator (1966)
Radio Shack Resistor/Capacitor/Inductor Identifier
Scholar's Pencil Box Calculator
Starrett Screw Calculator
TOTAL Oil - English to Metric Converter
Vacuum Oil First Aid Hints
Vickers Parts Selector
Wharco "Threadata"
Wine "In A Nutshell"
Not Slide Rules at all
Chinese "Suan-Pan" Abacus
Abacus
Charm Bracelet Abacus
Japanese Soroban (post-1950s)
Curta II
Davis Instruments "Ranger" Range Finder
Allen Engineering Scales
Gerber Variable Scale Ruler
Schubert Calculator
Arithma Addiator
Magic Brain Addiator
Wizard Addiator
McCabe Faultless System of Cutting