If you didn't think ahead 30 years, you will, eventually, need one of these!
Topside creeper.
Purchased it from micromark. I thought it was made for modeling purposes but the manufacturer (traxion engineered products) shows it for access to your vehicle motor, etc.
The hardest part was getting the 77 lb box from outside down to the basement.
It went together quickly: probably an hour.
I can now access that track that is 5' high and 3'-4' back along the wall 
The front casters has locking tabs.
The upper step section has 3 adjustment locations for tilting the upper section.
The height is also adjustable.
For storage, I had to angle, rotate the base to get through the laundry room 32" wide door.
Some release pins allow the base legs to fold up into a tidy, vertical position.
The legs tend to fall forward so I'll put a bungee cord around them.
Very well made and sturdy.
