Hi def345,
I don't understand what is FRA stands for, but if your telco would only decrease the number of lines going thru that PRI line. You need to block some lines on the MD110, so that the users won't experience getting a blank channel and wait for a time for it do disconnect. You would need to verify to the telco which channels would be removed so that the associated channels on the MD110 side could be blocked and removed. Regarding the TLU card being replaced, you need to verify from telco if they would not change the signalling or their interface on this.
More details would help.
Regards,
Sepay