I published this contribution on another forum already, but I thought you might appreciate to see it here too, the most appropriate place in my opinion!
Some images from my documentation illustrating some aspects and issues on Dinky Toys scales:
The well-known Memo no. 17157 Dinky, Dublo & Hornby scales sheet 1 of 30-10-1949 and brought up to date until 16-2-1961.
The same memo no. 17157 sheet 2.
The no. 25r Forward Control Lorry, the lonely member of the 1/6" or 1:73 scale category.
But there appears to be a companion, no. 23m 'Thunderbolt' Racing Car. The prototype's length was 30ft 5inch = 9.27m. As the length of the model is 127mm this
produces a scale of 127:9270 = 1:73.
Another companion of the Leyland Forward Control Lorry was the no. 984 Car Carrier, both models of the Leyland Beaver, but on quite different scales!
As it accommodates cars on the 1:45 scale, this model is presumed to have the same scale. The wheels, however, were limited to the 1:48 scale, which gives the wheel base a rather odd, unreal, elongated appearance.
Trojan Brooke Bond Tea Vans of Dinky Toys and Matchbox. Not exactly the same Marks but very similar and on deviating scales of 1:48 and 1:75 respectively.
A similar comparison for Vauxhall Cresta Saloon by Dinky and Matchbox on 1:45 and 1:78 respectively.
Bedford S-types by Dinky and Matchbox. The van and lorry are on 1:48 scales, the 3-Ton Army Wagon on 1:60, like the majority of its army companions.
Maudslays compared, the Horse Box on 1:48, the Luxury Coach, like the other buses and coaches on 1:76 scale.
The no. 25g (small) Trailer and the equally sized Four Wheel Hand Truck.
And this is their size relation if re-sized to the same scale.
Exactly the same wheel halves used on completely different scales: Diesel Roller 1:51, Garden Roller 1:16.
Again, the same wheels used on different scales: 1:43 for the Large Open Racing Car and 1:48 for the Foden eight wheeler. The wheels and tyres available were very important for the choice of scales adopted.
Dinky Toys of similar sizes, the Riley Saloon and the Daimler Ambulance. The scales are different though: 1:48 and 1:60.
The scales are the same now, but the ambulance has become much more voluminous than the Riley.
Land Rovers Mk I, models of the same basic prototype. The Mersey Tunnel Police Van is 1:45, the open Land Rovers are on the 1:38 scale.
A nice couple of comparative volume and size, the Trojan Van 'Esso' and the Studebaker Tanker 'Esso'. The first one on the 1:48 scale, the second 1:60.
The true scale correction here, producing a much bigger Studebaker.
Extreme Dinky scales together: the Queen Mary (and all other pre-war ships) on 1:1800, the Lawn Mower on 1:8!
Three Dinky models on similar size, the Land Rover, Tipping Wagon and Farm Produce wagon.
The same three models, now resized to the correct shared scale and size ratio.
Two models of similar real world vehicles in different scales: Dodge Rear Tipping Wagon on the 1:60 scale and the Leyland Comet with Hinged Tailboard on the 1:48 scale.
The same goes for the Leyland Comet Wagon and the Farm Produce Wagon of course.
But this happens when they are corrected to scale.
The Dinky Double Deckers would never have been such a commercial success if they would have been made on a larger than the 1:76 scale applied. Too expensive.
This produced the disadvantage that playing in combination with other Dinky Toys never felt quite well. The only scale solution was to join them by Dinky Toys made on the same 1:76, Dublo scale!
If you have similar additions, please add!
Kind regards, Jan
P.S.: I found the missing illustrations, which are now added below: