MTL bought lots of secondhand Leyland National1s in 1993/94 from various sources including Cumberland, East Midlands, Red & White, Badgerline, Fishwick and BHT Buses of Bournemouth, as well as having the original MPTE stock.
They were all fleet-numbered in the 52xx, 60xx and 61xx series, leaving room for the Neoplans (64xx-series) and Strider and Wright-bodied Volvo B10Bs (63xx, 65xx series).
The full list of MTL Manchester National1s in 1994 was;
MTL 5208(YBO 148T), 5209(SPC 269R), 5210(AKY 610T), 5211(AKY 611T), 5212(AKY 612T), 5223(UPB 323S), 5227(UTX 727S), 5230(DDW 430V), 5263(LDW 363P).
MTL 6002(SKF 2T), 6003(SKF 3T), 6005(SKF 5T), 6006(SKF 6T), 6007(SKF 7T), 6008(SKF 8T), 6009(SKF 9T), 6010(SKF 10T), 6012(SKF 12T), 6013(DAK 613V), 6020(YFB 970V), 6021(YFB 971V), 6023(KHT 123P), 6025(FBV 525S), 6028(GLP 428T), 6032(UHG 732R), 6033(TTC 533T), 6044(URA 604S), 6047(BAL 607T), 6048(BAL 608T), 6049(BAL 609T), 6051(UTU 981R), 6054(PVF 354R), 6056(XCW 956R), 6061(WUH 161T), 6064(NWO 464R), 6067(VKE 567S), 6070(VKE 570S), 6071(HCW 761N), 6074(NWO 474R), 6075(PCD 75R), 6077(BSF 767S), 6087(VFX 987S), 6088(UHG 748R), 6091(RAU 601R), 6092(OTO 592R), 6093(PCK 193P).
MTL 6178(TTC 538T), 6179(TTC 539T), 6180(TTC 540T), 6186(WGY 586S), 6187(WGY 587S), 6190(OHW 490R), 6192(OHW 492R) and 6197(NFB 597R).
(Source; North West Bus Handbook 1994).
Hope this helps