Hi Dennis and Welcome to Our Forum
Not sure Who or How many of us on here may be able to Help with regard to getting your Track Up & Running again.
Hopefully, Others will respond as well.
How Many 'Lanes' is it ?? and How Long ??,.. (Some Pics would be good), especially of the "Tower" you mentioned.
Depending on How it was Initially Set-Up, (component choices etc), it May or may Not be relatively easy to re-instate the Original equipment, else perhaps changing to some of the More Modern methodologies for lap counting might be Better/Easier !!??
There are a Number of Track Control / Lap Counting programs around,.. some Free (or atleast relatively Cheap) as far as I am aware and Depending on Number of lanes and types of cars you intend to run.
I think these are very Popular with Many Home Track setups;http://racecoordinator.net/https://trackmateracing.com/shop/en/
Most of the larger Commercial Raceways here us a System designed by Gary Johnson of 'Johnson Systems', which may also be a consideration, depending on What you might be looking for.
You may also be interested in looking at and perhaps also joining another Forum, where a couple of Australias Most Prolific Track Builders regularly 'Hang-Out' (including Gary J), as both he and Kim Axton 'Axman' have a Wealth of experience !!
You can have a bit of a look perhaps at This 'thread' on the above forum, of a recent very Nice Track build by one of the more Active members there, who may also be able to advise on some of the 'specifics' you require, re; Sensor choices and Software etc,.. see here;http://ausmcr.com/forum/index.php?/topic/11-pagey-new-track-build/&
Definitely worth having a 'click' through !!
Suitable Power Supplies are relatively easy to come by,.. but perhaps obviously, At a Price.
The "PowerTech" brand of PSU's seem to be Very Popular with many Home Track Owner/racers.
Also you may also be able to get some advice/help over on the 'Ausslot' forums; http://www.auslot.com/forums/index.php?/index
if you have no luck from the 'AusMcr' guys,.. (although I am Sure you probably Will,..
Anyway,.. Hope that helps,.. 'post' some piccies and let us know what transpires / develops,..