Our investment in hay making equipment is along the lines of yours. A few new things over the years.. most is OLD and reliable... and cost alot less than what the hay could have all cost...
One of the things around here is getting it made when it suits... everyone is making their own hay when ours needs to be made too... so pretty much got to have the equipment to do so.
And, several places we rent , there is both pasture and hay ground.... one right by me has pasture on one side of a busy road... 10 acre crop field across the road... no fences, no water etc.. deal is we rent it all and do what needs doing... pasturing cattle AND making hay... we have this place, with the 10 ac crop field, in part of the rotation for OG hay, sorghum-sudan, winter cover crop... and has been in corn once... another place has a 9 acre hay field not adjacent to any pasture and with no fences also... no water there either... we rotational graze the 3 big pastures and make hay off about 1/3 of one that is below the worst of the rocks and such... makes nice late pasture for the cows to come back to and then we can load them out of that section.
Like you, been many years ago that we invested in most of the equipment... and the older tractors and such are easy to work on, and just very reliable... Prefer it that way...
Just finished about 15-20 acres in 3 pieces of mostly just mixed grass and hay... used the Ford 4600 and a 7 on a side long wheel rake... tractor is great on fuel, stable on hills due to lower center of gravity... easy to start, can roll it if necessary, no electronic crap....and all I need on some of these hillsides... Easy to hook and unhook any hydraulics... easy to hook and unhook other equipment... use it for tedding and raking mostly... I wouldn't take 25,000 for it.... Only 55-60 HP, diesel, 2wd... no loader no canopy.... Got it's "sister.".. ford 6600 with loader/spear and use "pallet fork" type lifter on back for moving hay rolls... bought both used from friends estate... not kept inside so paint is mostly gone... but they chug right along...