Archer MR200 V1 restore to stock firmware

Hi, everyone!
I have an TP-link archer mr200 v1, with orange firmware. How can i put the stock tp-link firmware inside?
the orange firmware has not pptp version of vpn, and i need it. No need for openwrt because i need only pptp connection by lte. Can i be helpt?
Thak you!
P>S. the modem itself seems not to be locked, it is working with other sim card...

the info might work for the TP-Link firmware too.

Not sure that it helpt me.
I have the orange firmware and the tplink firmware. Booth for V1 mr200. What should i do?
Cut the bootloader from tplink and add the orange one?
It is the solution?
I have look trough bin files and the beginning are not the same for sure.

There's a prefixed fw posted in the 2nd thread, but it's openwrt, not stock.

They mention the boot loader differs, in the 1st thread.

So far no solution,
As i understood i must change the header on tplink firmware with orange one.
I don t know how to do this.
I have try some files from openwrt and no success. I mean pre-built ArcherC2V1_tp_recovery.bin from different sources. Tftp not working try 10 times and fail, continues to normal boot.
I think that orange somehow make that u-boot refuses to flash from tftp.
So i need to prepare an stock firmware with orange header.
Is an idea,
I see that a lot of discussions on this router with no particular solutions.
It is a poor device but it can be help to exchange an hg655 + 4g phone for vpn connection with only one device. And leave the phone intact.