Half asking for help identifying, half just chatting about what ive done, what any of you would do?

We have an old FZ bedmill (supposedly fz4 from 1968 but cannot confirm) That uses an oddball or unique tool holder that ive not been able to find anything on except that in the manual it says its a morse taper 4, (MTB4 specifically in this case). However the tool holder has flat cheeks at the end of the taper to fit inside a recessed rectangular hole on the nose of the spindle and has a reversed angle flat for a locking screw.

My major three and half issues were or are, while we have some of the smaller tool holders we only have like 10 sizes of collet, common endmill shaft sizes, so drill bits that arent those sizes or close become an issue, which ive sort of dealt with. 2 The large collet holder for the monster endmills snapped before i even started working here so we cant use our 1-1/2"+ shaft endmills on this machine. 3. the misc. tool holders shafts arent compatible with modern standard fits so i have to get creative and modify off the shelf modern MTB4 tool holders but finding the right tool holder shaft with the right standout to be able to modify for the cheeks is challenging especially for the larger endmills that we'd like to use on some projects.Oh and half issue is i dont like how much most if not all the tool holders protrude from the nose since it adds wobble/vibration compared to my modified amazon holders.

Ive modified a couple MTB4 er 32 collet holders off amazon kinda haphazardly with the surface grinder to fit it, and it works well enough, though sometimes it feels like they are a little off but hard to tell if its the tool holder or collet. but limited to sub 1" shafts. Ive tried to create a tool holder/chuck adapter before but it was a little above my skill level and the capabilities of the condition of the lathes at the time. 

Also im technically down one of our 3 original "smaller" tool holders cause the nut of one of them is stuck to a gear puller cause someone left the tool holder in there for 2+ years or so and it got stuck. They used the bridgeport knee mills more often since we were limited by tool holding... so before i started working here they were the only one using it. i'm maitnence so i use these machines to create parts, they are a vacuform mold/tool maker and generally only work in wood and aluminum where im working in various steels and such. 

And just for anyone curious the list of compatible useable tools/holders we have are 

2x "smaller" collet holders 

1x flycutter

1x boring bar

1x 6" wide face/endmill like thing...

1x short slotted driving shaft for right angle head attatchment we have.

1x long proturuding slotted shaft for?

2x misc internally threaded shafts (shown below) for ?

I wanna get a more modern insert facemill holder for it, some large diameter 1 to 2" endmill shaft holders to use our big endmills again, along with an arbor shaft at some point... but figured id pick yalls brains first before jumping into modifying. 

for the arbor shaft i was consideing getting an MTB4 lathe testbar turning shaft down to size cutting a keyway and seeing if i could find the spacers/nut somewhere. The facemill and large tool holders... being on the lookout for ones that have the clearance to modify the cheeks onto. any thoughts ideas or suggestions id love to hear them... 

Odd Mill tool holder identification/discussion?