Ive had some success using big morse bits in my lathe by mounting the bit up in the tailstock, then using the center steadyrest to support the bit in the middle and a big set of vicegrips to help keep it from grabbing and rotating..gotta take light cuts..even then it sometimes still grabs and rotates..biggest I can go is Morse 4 in my lathe tailstock..with using one morse size adapter the torque force overcomes the tang on the bit or adapters and shears it off..kinda like a safety fuse..I used to drill holes in steel flat plate that way, mount it up in a 4-jaw chuck..now I use the press..gotta use what u got.

U got a deal on those bits even if you only needed one..hell Ill give ya $50 for the balance..$350 in gas later I might make Arrowsmith,IL LOL