Commiserations. This has happened a couple of times to me and it's really distressing.
Car boot sales? I've found
Baconsdozen's tools pretty good for Whitworth spanners etc.
In fact you don't need too many tools for basic maintenance - an assortment of Whit spanners, flat bladed screwdrivers, range of hammers.....
A good quality big adjustable is useful for wheel nuts etc although the purists will shudder.
