Cisco MGCP + SIP\SCCP call forwarding?

Question

Telephony

Good day to all!
I comprehend the basics of IP-telephony, and along the way the following task turned up:
We have a Coral PBX in the organization, it has the main analog / digital phones + city numbers on E1 + several ip gateways for branches. The gateways are controlled by the MGCP protocol.
We have 2 Cisco 2821,2921 routers, without any T1 \ E1 boards and several SIP \ SCCP phones.
There was an idea - to lift on tsiska CME, to connect with the Coral, to tie IP phones to tsiska and to arrange them on branches, thereby having saved on gateways.
Actually, the question is, is it possible to somehow transfer calls from/to SIP\SCCP domain over the MGCP channel, implementing just such a scheme?

It is not yet possible to purchase SIP licenses for Coral, as well as to purchase T1 \ E1 boards for cisco routers.
PS: If the question is stupid, I ask you not to kick much - I'm new to telephony). Thank you all in advance!