I own 6 of those. I bought my first one in 1978 which was when they were advertised. The wheels are fine scale. That is OW5 but with a smaller treads. If you have track issues they will find them. They are good runners. 4482, 117 and 114 ate all Q4b,s.
You need another one...
https://www.ebay.com/itm/O-Sca...nal-box/283445691958