You don`t have to do the Lyman sights, do a M1928-A1 (Most of which were M1921`s but with different bolt and weaker recoil springs for less rate of fire) with the cheapo flat metal rear sight, which is what I am going to do even though my Thompson probably fires closer to 900 bb`s a minute.
Some tips for you:
You want the flat metal that you plan to epoxy onto the receiver to be 5-6mm in thickness, depending on the sort of paint you want to use.
If you like patina looks, go for Steel or Iron which will sort of brown itself out if you use thin paint and go for the blueing process.
I got lucky and found some old home-made door hinges (For really large doors) made out of flat iron, in my barn.
I am planning to cut these with a grinder and just epoxy onto the receiver, grind/dremel the round edges and it should look proper.
Some further details and thoughts from my build (Which will eventually make it into it`s own thread once I`m 100% finished)
Notice that on the back of the thompson receiver, which on the M192x protrudes outwards, is actually the hole where the M192x stock`s catch hinges into (same sort of patent as the magazine catch hinges onto the magazine to keep it in place) but would also need to dremel a rail on the bottom of both sides of the lower receiver, getting this just right is going to be tricky, but the hardest part consists of hollowing out the stock in order to fit the battery so I am considering just keeping the plastic M1 stock for now until I can come up with a good idea, I know a guy that can get some Thompson stuff but for now I am holding off on M1928 stock.
I broke my M1 actuator plate when experimenting with the hole size on the rear of the Actuator crack (Trick is to make it just big enough for the Bolt handle to come out of it when you pull the bolt back, but not too big or it will look stupid) as it broke in two when I tried to take it out (Due to the adjustable rear sight assembly inside the rear of the receiver, requiring me to bend the actuator plate much more than usual) and ended up having to make a bunch of new plates until finally figuring out how they should be, also I had to grind down the rail inside the receiver that stops the M1 actuator plate from wobbling around inside the receiver as you pull the bolt back. Just in order for the top based actuator plate to not be slightly tilted.
Also I had to remove that plate on top of the gearbox in order to have room for the actuator plate on top, as well as grinding off about 0.4 to 0.5mm off the top of the gearbox, with a dremel, the gearbox does not seem weakened in the least though!
As well as completely grinding away (Litterarily removing) the rear sight assembly inside the reciever, both in order to be able to take off the actuator plate without bending it too much, as well as being able to pull the bolt all the way back. I am also experimenting on a derivation of the simple blowback mod for M1, with much more thought to being robust (Making it the first custom M1928 aeg with top bolt actuator airsoft with blowback ever, to my knowledge anyways)
One thing is to make a ACM M1928 (With the wrong receiver) or TM M1 (Requiring a Phoenix 1928 front kit) look pretty much like a M1928 (With correct receiver, more or less) at 5 paces, but making it exactly right at close inspection by trained eyes however has proven to be a much harder task than I anticipated, so I can certainly understand your grim thoughts, but even with just Dremel and some good materials and a little know-how, it`s not impossible
I too am looking for the cabnet knob but so far no go, @ hairyapple can I ask you which store sells it and if they have a webpage?
I am considering ordering a small bulk those, in case I mess up on threading the screw hole for the first one, I will have a few more to experiment on. A friend of mine also wants a custom M1928 receiver (He`ll be going for the Cybergun 1928, so he`ll be getting the M1928 ears, which I want so badly but which also cannot be bought separately..) and in case I decide to modify a few more receivers just for the heck of having a full M1921/28 rack (They look so cool in Public Enemies and that movie Dillinger from the 60`s/70`s)
Also, if anyone knows of a Cybergun M1928 rear sight protector for sale separately, I`d really appreciate a heads up in my direction!
