Wish I could be of more help, but the fact that Heinkel's master archives at Rostock were destroyed by Allied bombing has eliminated precious data blue-prints about the He280, the He178 and of course, the He100.
If it'll be of any help, I'll post data on all the He280 airframes that might help you in your search:
V1 DL+AS (WkNmr 280-00 0001) powered by As014 - first flew 22 Sep 40, crashed 13 Jan 43
V2 GJ+CA (WkNmr 280-00 0002) powered by HeS8A - first flew 30 Mar 41, crashed 26 Jun 43
V3 GJ+CB (WkNmr 280-00 0003) powered by HeS8A - first flew 5 Jul 42, captured April 45
V4 -none- (WkNmrs 280-00 0004) used for spare parts due to lack of engines - on records until end of 44
V5 -none- (WkNmr 280-00 0005) intended prototype - never completed
V6 -none- (WkNmr 280-00 0006) used for experimental - never completed
V7 NU+EB (WkNmr 280-00 0007) "V-tail" version (no mention of engine type) - first flew 19 Apr 43, records end April 45
V8 NU+EC (WkNmr 280-00 0008) powered by Jumo004 - first flew 19 Jul 43, records end April 45
V9 - partially built, no records
V10 through V12 - intended He280B version, planned but never built
I have read that one of the He280 airframes were tested with the Argus pulsejet, but I have never seen any test data regarding that.