Took the starter off and used a repair kit to change starter solenoid contacts and plunger. Fitting the starter back on I fitted the two bolts and then went to fit the nut at the back. Dropped the nut and lost it somewhere. I went to find another and realised I had been trying to fit the nur for the cable. I then saw stuck to the bottom of my magnetic tray, the spring for the plunger. Glad I had made the error with the nut and noticed before fitting the rear nut and using it. I don't know what the effect of the plunger sticking in might be. All finished and working now.

Serendipity? Pure blo ody luck mate! And who was the nice person who bought you a magnetic tray for Christmas?
I hinted to wifey about one of these, more than once, and normally she "hears" this sort of thing, must need a hearing aid, still waiting!
That'll teach you to put the nut in it!
I have to work on gravel, thick stuff, lost the locking nut socket thing once, raked and sieved a coupla tons of gravel, never found it, had to drive all the way to Christchurch LR to buy a new one, GRRR!
Now I have two! It just suddenly appeared in the gravel years later. Yes it IS fu cking deep!
Anyway, glad your solenoid or pinion or whatever it is, will not be stuck in once it has done it's job!

I once found a set of our keys on a branch of a tree in the front garden They were rusty and had obviously been there a few years. One other bonus today is that I noticed that I had left a spanner on the clutch bleed nipple when i bled it last.

These things do happen, fortunately not always with disastrous results!
You were lucky not to get burgled with the keys, you must live in a very safe place!

I once found a wide bolster, more or less new, under the bonnet of a Renault 17 I had just had a mobile welder working on, he was happy to have it back.
I have similarly found a 8 mm spanner inside a panel on a new Toyota, must have been there since manufacture.
But the funniest was after going to the National Kit Car show at Stoneleigh where we found ourselves helping each other with various repairs and adjustments going on, more than usual. I lent spanners etc to two members of my club and at the end of the weekend noticed I had one spanner too many and one too few. (Using a tool roll helps to keep track!). No one seemed to know what had happened, so I wrote a pastiche in Hercule Poirot style, in the monthly newsletter, to try and help sort it out. This was appreciated but, still nothing. But about 3 months later a Cobra owner looked up under the nearside front wheel arch and there was my spanner, still attached to a suspension bolt! Lord knows how it never fell off! Simialr to your clutch bleed spanner. I still have the extra spanner, and what is weird is that all my tools at the time were AF as all three cars worked on were based on old Brit vehicles, two, Jag and one Morris, or BL.
Wifey is now getting me the magnetic dish for my Valentine's Day present! Who says romance is dead!